A borate type polymer, a preparation method and application thereof

Abstract

The application belongs to the technical field of polymers, and particularly relates to a borate type polymer and a preparation method thereof, and application of the borate type polymer as a full solid or gel state single-ion conductor polymer electrolyte in a separator, a positive electrode or a negative electrode of a lithium ion battery, a sodium ion battery, a metal lithium battery or a metal sodium battery. The borate type polymer is a novel polymer, and anions of inorganic salts such as inorganic lithium salts or inorganic sodium salts are fixed on a polymer chain through chemical bond action, movement of the anions is limited, when the borate type polymer is applied as a single-ion conductor polymer electrolyte, only cations such as lithium ions or sodium ions migrate, the number of cation migrations can be greatly improved, and influence caused by concentration polarization can be effectively avoided. The borate type single-ion conductor polymer electrolyte includes a full solid polymer electrolyte and a gel polymer electrolyte, and problems of low ion conductivity, poor thermodynamic stability and poor mechanical performance of an existing polymer electrolyte are solved.

Description

Technical Field

[0001] This invention belongs to the field of polymer technology, specifically relating to a borate polymer and its preparation method, as well as its application as an all-solid or gel single-ion conductor polymer electrolyte in the separator, positive electrode or negative electrode of lithium-ion batteries, sodium-ion batteries, lithium metal batteries or sodium metal batteries. Background Technology

[0002] Currently, lithium-ion or sodium-ion batteries commonly use organic small-molecule liquid electrolytes as the electrolyte, which often leads to problems such as lithium / sodium dendrite growth, electrolyte leakage, and volatilization, posing significant safety hazards such as combustion and even explosion. Solid-state batteries, on the other hand, use solid electrolytes instead of liquid electrolytes and are applied in the field of new energy vehicles, significantly improving their safety and lifespan.

[0003] As a major category of solid electrolytes, polymer electrolytes mainly include all-solid polymer electrolytes and gel polymer electrolytes, exhibiting good safety, flexibility, and excellent interfacial contact properties. All-solid polymer electrolytes typically dissolve inorganic salts (lithium or sodium salts) in a high-molecular-weight polymer, achieving ion conduction through the chain segment movement of polymer molecules. Therefore, their ionic conductivity is relatively low at room temperature, generally around 10⁻⁶. -7 Up to 10 -6 S / cm. Gel polymer electrolytes are composed of polymers, plasticizers (organic solvents), and inorganic salts. Cations (lithium ions or sodium ions) are conducted within the polymer matrix network structure that is swollen into a gel by the organic solvent. The ionic conductivity increases with the increase of the proportion of organic solvent, and is much higher than that of all-solid-state polymer electrolytes. However, when the proportion of organic solvent exceeds a certain value, the electrochemical performance of gel polymer electrolytes improves, but the mechanical properties deteriorate, and it is detrimental to the safety performance of the battery.

[0004] Polymer electrolytes are typically dual-ion conductors, meaning that both cations (lithium ions or sodium ions) and anions migrate during charging and discharging. However, anions do not react with the electrodes and tend to accumulate at the electrodes, causing concentration polarization, which increases the battery's internal resistance and reduces its energy efficiency.

[0005] Therefore, current polymer electrolytes still suffer from problems such as low ionic conductivity, poor thermodynamic stability, and poor mechanical properties. Summary of the Invention

[0006] The purpose of this invention is to provide a novel borate-type polymer and its preparation and application. This novel borate-type polymer immobilizes inorganic salt (inorganic lithium or sodium salt) anions on the polymer chain through chemical bonds, restricting anion movement. When used as a single-ion conductor polymer electrolyte, only cations (lithium or sodium ions) migrate, significantly increasing the cation transference number and effectively avoiding the effects of concentration polarization. This invention's borate-type single-ion conductor polymer electrolyte includes all-solid-state polymer electrolytes and gel polymer electrolytes, addressing the problems of low ionic conductivity, poor thermodynamic stability, and poor mechanical properties of existing polymer electrolytes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a borate-type polymer, the structure of which is: (XY) n ,in,

[0009] X is a cyclic group consisting of a hydrocarbon group or a substituted hydrocarbon group, B and O cyclized together, wherein the number of units in the ring is ≤20;

[0010] Y is a short chain segment of a small molecule composed of a hydrocarbon group or a substituted hydrocarbon group, or a long chain segment of a polymer composed of a hydrocarbon group or a substituted hydrocarbon group.

[0011] The substituted hydrocarbon group includes halogenated hydrocarbon group, oxygen-containing hydrocarbon group, sulfur-containing hydrocarbon group, phosphorus-containing hydrocarbon group or nitrogen-containing hydrocarbon group; n is a positive integer ≥1.

[0012] Furthermore, the structural formula of X is shown in general formula (1), general formula (2), or general formula (3) as follows:

[0013]

[0014] In this context, the curve represents a half bond; R1 and R2 are each independently selected from hydrocarbon groups, halohydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups, or amino-containing hydrocarbon groups; M is selected from Li and Na; W is selected from O and NR; R is a hydrogen atom or an alkyl group; and m is a positive integer ≥1.

[0015] Furthermore, X includes at least one of the following structures (X1) to (X11):

[0016]

[0017]

[0018] In this context, the curve represents a half bond; M is selected from Li and Na, W is selected from O and NR, R is a hydrogen atom or an alkyl group, and m is a positive integer ≥1;

[0019] Furthermore, in the structure of the borate polymer, Y is a short-chain segment of a small molecule or a long-chain segment of a high molecule containing at least one of a hydrocarbon group, an ether bond, an amide group, an imino group, an ester group, or a carbonyl group. Preferably, Y includes at least one of the following structures (Y1) to (Y7):

[0020]

[0021] In this context, curves represent half bonds; R3 is independently selected from hydrocarbon groups, imino groups, oxygen-containing hydrocarbon groups, or nitrogen-containing hydrocarbon groups; R4 and R5 are independently selected from hydrocarbon groups or halogenated hydrocarbon groups; R6 is independently selected from hydrocarbon groups or substituted hydrocarbon groups; and x and y are both positive integers ≥1.

[0022] Furthermore, the number of units in the ring is ≤12, preferably ≤8;

[0023] And / or: the hydrocarbon group has 1-5 carbon atoms, preferably 2-4;

[0024] And / or: the haloalkyl group has 1-5 carbon atoms, preferably 2-4;

[0025] And / or: the sulfur-containing hydrocarbon group has 1-5 carbon atoms, preferably 2-4;

[0026] And / or: the nitrogen-containing hydrocarbon group has 1-5 carbon atoms, preferably 2-4;

[0027] And / or: the oxygen-containing hydrocarbon group has 1-10 oxygen atoms, preferably 2-5;

[0028] And / or: The oxygen-containing hydrocarbon group is selected from hydrocarbon groups containing -C=O, -O-, -(C=O)- or -COO-.

[0029] Secondly, the present invention provides a method for preparing the above-mentioned borate polymer, wherein the borate polymer is synthesized by copolymerization, and the copolymerization method includes three types, wherein...

[0030] The first copolymerization is as follows: the first substance containing Y undergoes a dehydration condensation reaction with the boric acid and the inorganic salt containing M required for the formation of X, to generate a borate-type polymer containing a borate structure, as shown in Formula I:

[0031]

[0032] The second type of copolymerization involves a dehydration condensation reaction between the first substance containing Y and the borate containing X and the inorganic salt containing M, resulting in a borate-type polymer linked by borate groups, as shown in Formula II.

[0033]

[0034] The third type of copolymerization involves a dehydration condensation reaction between the second Y-containing substance and the X-containing borate to generate a borate-type polymer linked by borates, as shown in Formula III.

[0035]

[0036] R1 and R2 are each independently selected from hydrocarbon groups, halohydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups or amino-containing hydrocarbon groups, M is selected from Li and Na, W is selected from O and NR, R is a hydrogen atom or alkyl group, m and n are both positive integers ≥1, and the curve represents a half bond.

[0037] In the first copolymerization and the second copolymerization, the first Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows:

[0038] In this case, N1 is independently selected from hydroxyl or carboxyl groups;

[0039] The first Y-containing substance is preferably a Y-containing small molecule or Y-containing polymer having two hydroxyl groups, two carboxyl groups, or one hydroxyl group and one carboxyl group at each end;

[0040] In the third copolymerization, the second Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows:

[0041] N2-Y-N2, wherein each N2 group is independently selected from hydroxyl, carboxyl, or amino groups;

[0042] The second Y-containing substance is preferably a Y-containing small molecule or Y-containing polymer with a single hydroxyl group, a single carboxyl group or a single amine group at both ends;

[0043] In the second and third copolymerizations, the X-containing borate is a cyclic polymeric borate with borate groups at both ends, and the X-containing borate is synthesized from boric acid, an inorganic salt containing M, and an organic compound containing hydroxyl or carboxyl groups;

[0044] In the synthesis of the first copolymerization, the second copolymerization, the third copolymerization, and the X-containing borate, the M-containing inorganic salt is one of an inorganic lithium salt or an inorganic sodium salt.

[0045] Furthermore, the first Y-containing substance is obtained by chemical modification of the second Y-containing substance.

[0046] Furthermore, the organic compound is at least one of tartaric acid, pentaerythritol, diglycerol, di(trimethylolpropane), and ethylenediaminetetraacetic acid.

[0047] Thirdly, the present invention provides an electrolyte comprising the above-mentioned borate polymer.

[0048] Furthermore, the electrolyte is a single-ion conductor polymer electrolyte.

[0049] Furthermore, the single-ion conductor polymer electrolyte is an all-solid polymer electrolyte or a gel polymer electrolyte, with a cation transference number > 0.9, and the cation is either lithium ion or sodium ion.

[0050] Furthermore, the ionic conductivity of the all-solid polymer electrolyte is ≥5*10⁻⁶. -6 S / cm.

[0051] Furthermore, the liquid absorption rate of the gel polymer electrolyte is 1%-1000%, preferably 1%-500%, and more preferably 1%-300%.

[0052] And / or: the ionic conductivity of the gel polymer electrolyte is ≥1*10 -5 S / cm, preferably, the ionic conductivity of the gel polymer electrolyte is ≥1*10 -4 S / cm.

[0053] Furthermore, the preparation method of the all-solid polymer electrolyte membrane is as follows: a borate polymer is made into a solution, the solution is coated into a film, and dried to obtain the all-solid polymer electrolyte membrane.

[0054] Furthermore, the preparation method of the gel polymer electrolyte membrane is as follows: a borate polymer is made into a solution, the solution is coated into a film, dried, and then absorbed with an organic solvent to obtain the gel polymer electrolyte membrane.

[0055] Furthermore, there are two ways to absorb organic solvents after drying: one is to immerse the dried film in an organic solvent, and the other is to spray an organic solvent onto the dried film; preferably, an organic solvent is sprayed onto the dried film, wherein the mass ratio of borate polymer to organic solvent is 1:0.1-10.

[0056] Furthermore, the organic solvent is selected from one or more of acetonitrile, succinic anion, adiponitrile, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate, propyl acetate, 1,4-dioxane, 1,4-butyrolactone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, sulfolane, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and dipropyl carbonate.

[0057] Fourthly, the present invention provides a diaphragm comprising the above-described borate polymer.

[0058] Furthermore, the membrane is a single-ion conductor polymer membrane.

[0059] Furthermore, the single-ion conductor polymer membrane is an all-solid polymer membrane or a gel polymer membrane, with a cation transference number > 0.9, and the cation is either lithium ion or sodium ion.

[0060] Furthermore, the ionic conductivity of the all-solid polymer membrane is ≥5*10⁻⁶. -6 S / cm.

[0061] Furthermore, the liquid absorption rate of the gel polymer membrane is 1%-1000%, preferably 1%-500%, and more preferably 1%-300%.

[0062] And / or: the ionic conductivity of the gel polymer membrane is ≥1*10 -5 S / cm, preferably, the ionic conductivity of the gel polymer membrane is ≥1*10 -4 S / cm.

[0063] Furthermore, the preparation method of the all-solid polymer membrane is as follows: a borate polymer is made into a solution, the solution is coated into a film, and dried to obtain an all-solid polymer membrane.

[0064] Furthermore, the preparation method of the gel polymer membrane is as follows: a borate polymer is made into a solution, the solution is coated into a film, dried, and then absorbed with an organic solvent to obtain a gel polymer membrane.

[0065] Furthermore, there are two ways to absorb organic solvents after drying: one is to immerse the dried film in an organic solvent, and the other is to spray an organic solvent onto the dried film; preferably, an organic solvent is sprayed onto the dried film, wherein the mass ratio of borate polymer to organic solvent is 1:0.1-10.

[0066] Furthermore, the organic solvent is selected from one or more of acetonitrile, succinic anion, adiponitrile, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate, propyl acetate, 1,4-dioxane, 1,4-butyrolactone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, sulfolane, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and dipropyl carbonate.

[0067] Fifthly, the present invention provides a battery, which is one of a lithium-ion battery, a sodium-ion battery, a lithium metal battery, or a sodium metal battery, and the battery includes the above-mentioned borate polymer.

[0068] Furthermore, both the lithium-ion battery and the sodium-ion battery are single-ion conductor polymer batteries.

[0069] Furthermore, the single-ion conductor polymer battery includes a positive electrode plate, a negative electrode plate, an separator, and an electrolyte; wherein the positive electrode plate contains the borate polymer; and / or, the negative electrode plate contains the borate polymer; and / or, the separator contains the borate polymer; and / or, the electrolyte contains the borate polymer.

[0070] Furthermore, the borate polymer is added to the positive or negative electrode plate. The specific process is as follows: the borate polymer is mixed with the positive or negative electrode active material, conductive agent, and binder to form a slurry, which is then coated on the current collector and dried to obtain the positive or negative electrode plate.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] 1. The borate polymer of the present invention is a novel borate polymer with the following advantages: First, inorganic salt (lithium salt or sodium salt) anions are fixed to the polymer chain through chemical bonding, restricting the movement of anions and allowing only cations (lithium ions or sodium ions) to migrate, making it a single-ion conductor polymer with higher ionic conductivity; second, the introduction of borate improves thermodynamic stability; and third, borate can copolymerize with polymers, significantly improving mechanical properties. Furthermore, the copolymerization of borate and polymers forms a polymer that combines rigidity and flexibility, which is beneficial for the conduction of lithium ions or sodium ions and improves ionic conductivity.

[0073] 2. The method for preparing borate-type polymers of the present invention is simple and easy to implement, with low raw material costs, and is suitable for large-scale production.

[0074] 3. The electrolyte and / or separator of the present invention contains a borate-type single-ion conductor polymer, which has superior performance compared to dual-ion conductor polymer electrolytes and / or separators. Compared with polymer electrolytes and / or separators that are composited with fluoroborates by physical methods, the borate in the electrolyte and / or separator of the present invention is not a small molecule salt, but a polymer, and is of the single-ion conductor type. This can restrict the movement of anions and effectively avoid the effects of concentration polarization (anions that do not react with the electrode are prone to accumulate at the electrode, causing concentration polarization, which increases the internal resistance of the battery and reduces energy efficiency). Moreover, it only allows cations (lithium ions or sodium ions) to migrate, greatly increasing the lithium ion transference number or sodium ion transference number, and has higher lithium ion conductivity or sodium ion conductivity.

[0075] 4. The all-solid-state polymer electrolyte and / or separator of the present invention has an ionic conductivity ≥5*10⁻⁶ compared to traditional all-solid-state polymer electrolytes and / or separators. -6 S / cm. The polymer electrolyte and / or diaphragm exhibit good mechanical properties and thermodynamic stability.

[0076] 5. The gel polymer electrolyte and / or separator of the present invention exhibits superior performance compared to conventional gel polymer electrolytes and / or separators, with higher cation transference numbers (lithium ion transference number or sodium ion transference number). It also maintains high room temperature ionic conductivity ≥1*10⁻⁶ even under low absorbance conditions, such as 20-50% absorbance. -4 Compared to all-solid polymer electrolytes and / or membranes, the gel polymer electrolyte and / or membrane exhibit higher ionic conductivity (S / cm) due to the introduction of plasticizers such as organic solvents. The gel polymer electrolyte and / or membrane also demonstrate excellent mechanical properties and thermodynamic stability.

[0077] 6. The battery of the present invention has low internal resistance, high energy efficiency, good rate performance, good safety, and long cycle life. Detailed Implementation

[0078] To make the objectives, technical solutions, and advantages of this invention clearer, the following embodiments are provided to further illustrate the invention. The embodiments of this invention are implemented based on the technical solutions of this invention, and detailed implementation methods and processes are given. Those skilled in the art should understand that the embodiments are merely illustrative of the invention and should not be considered as specific limitations on the invention. Furthermore, the scope of protection of this invention is not limited to the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0079] In the embodiments of this invention, process parameters not specifically specified are generally performed under conventional conditions. Unless otherwise specified and / or stated, all numerical values ​​relating to component amounts are "molar or mass values ​​or ratios" throughout. Unless otherwise stated, all raw materials used in this invention are available from commercially available products.

[0080] In this invention, the endpoints and any values ​​of the disclosed ranges are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0081] The present invention provides the following specific implementation methods:

[0082] According to a first aspect of the present invention, a borate polymer has the following structure: (XY) n ,in,

[0083] X is a cyclic group consisting of a hydrocarbon group or a substituted hydrocarbon group, B and O cyclized together, wherein the number of units in the ring is ≤20 (e.g., 20, 15, 10, 5, etc.);

[0084] Y is a short chain segment of a small molecule composed of a hydrocarbon group or a substituted hydrocarbon group, or a long chain segment of a polymer composed of a hydrocarbon group or a substituted hydrocarbon group.

[0085] The substituted hydrocarbon group includes halogenated hydrocarbon group, oxygen-containing hydrocarbon group, sulfur-containing hydrocarbon group, phosphorus-containing hydrocarbon group or nitrogen-containing hydrocarbon group; n is an integer ≥1 (n such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.).

[0086] In the technical solution of this invention, the borate polymer structure contains X and Y, wherein X can be a cyclic group composed of hydrocarbon groups, B and O cyclization, or a cyclic group composed of substituted hydrocarbon groups, B and O cyclization; Y can be a small molecular short chain segment composed of hydrocarbon groups, a small molecular short chain segment composed of substituted hydrocarbon groups, a high molecular long chain segment composed of hydrocarbon groups, or a high molecular long chain segment composed of substituted hydrocarbon groups.

[0087] Since boron is a typical example of an electron-deficient atom, boric acid is a typical Lewis acid, which can ionize to form a small amount of B(OH)4 when dissolved in water. - and H + The presence of ions makes the solution weakly acidic. In the presence of polyhydroxyl, carboxyl, sulfonic acid, and amino groups, boric acid can undergo esterification to form stable borate ester complexes, producing more H+. + The acidity of the solution is significantly enhanced when ions are present. When alkaline inorganic salts such as LiOH or NaOH are present in the solution, borate esters can undergo a neutralization reaction with the base to form borates and water. As water is removed, the reaction proceeds in the forward direction, forming the final product borates, such as organic lithium or organic sodium or organic borate.

[0088] The borate polymer of this invention can be either a lithium borate or sodium borate polymer, depending on the cation. Regardless of the cation, the X (borate unit, which can be either a lithium or sodium borate group) in its structure is centered on B, forming a large π-conjugated system with oxygen-containing ligands. The strong electron-withdrawing effect effectively disperses the negative charge on B, thereby reducing the interaction between the cation (lithium or sodium ion) and B, making the lithium or sodium ion readily dissociable. Furthermore, since the anion is fixed to the polymer chain through chemical bonds, forming a single-ion conductor polymer, the ion transference number of lithium or sodium ions is close to 1, thus exhibiting high ionic conductivity. When all groups of Y in its structure are hydrocarbon groups, it represents the most common and common structure in borate polymers. When it contains halogenated hydrocarbon groups, the strong electron-withdrawing effect of halogen atoms such as F further promotes the dissociation of lithium or sodium ions. Similarly, oxygen-containing, sulfur-containing, phosphorus-containing, or nitrogen-containing hydrocarbon groups all further promote the dissociation of lithium or sodium ions due to their electron-withdrawing effects, thus increasing the ionic conductivity of the polymer. In addition, copolymerization of Y and X can also increase the flexibility of the polymer.

[0089] As an optional embodiment of the present invention, the structural formula of X is shown in the following general formula (1), general formula (2) or general formula (3):

[0090]

[0091] In this context, the curve represents a half bond; R1 and R2 are each independently selected from hydrocarbon groups, halohydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups, or amine-containing hydrocarbon groups; M is selected from Li and Na; W is selected from O and NR; R is a hydrogen atom or an alkyl group; and m is a positive integer ≥1 (m such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.).

[0092] In this invention, in all structural formulas, the groups at different positions can be independently selected as the same or different groups. For example, in the aforementioned general formula (1), the R1 at both ends can be two completely identical groups or two completely different groups. Similarly, in the Y5 structure below, the R6 inside the parentheses and the R6 outside the parentheses can be two completely identical groups or two completely different groups.

[0093] As an optional embodiment of the present invention, X includes, but is not limited to, the following structures (X1) to (X11):

[0094]

[0095] In this context, the curve represents a half bond; M is selected from Li or Na, W is selected from O or NR, R is a hydrogen atom or an alkyl group, and m is a positive integer ≥1 (m such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.).

[0096] As an optional embodiment of the present invention, in the structure of the borate polymer, Y is a short-chain segment of a small molecule or a long-chain segment of a high molecule containing at least one of a hydrocarbon group, an ether bond, an amide group, an imino group, an ester group, and a carbonyl group. Preferably, Y includes, but is not limited to, the following structures (Y1) to (Y7):

[0097]

[0098] In this context, the curve represents a half bond; R3 is independently selected from hydrocarbon groups, imino groups, oxygen-containing hydrocarbon groups, or nitrogen-containing hydrocarbon groups; R4 and R5 are independently selected from hydrocarbon groups or halogenated hydrocarbon groups; R6 is independently selected from hydrocarbon groups or substituted hydrocarbon groups; x and y are both positive integers ≥1 (x and y can be such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.).

[0099] As an optional embodiment of the present invention, the number of ring units is ≤12 (e.g., 12, 10, 8, 6, 4, 2, etc.), and preferably the number of ring units is ≤8 (e.g., 8, 7, 6, 5, 4, 3, 2, 1, etc.).

[0100] And / or: the hydrocarbon group has 1-5 carbon atoms (e.g., 1, 2, 3, 4, 5), preferably 2-4;

[0101] And / or: the haloalkyl group has 1-5 carbon atoms (e.g., 1, 2, 3, 4, 5), preferably 2-4;

[0102] And / or: the sulfur-containing hydrocarbon group has 1-5 carbon atoms (e.g., 1, 2, 3, 4, 5), preferably 2-4;

[0103] And / or: the nitrogen-containing hydrocarbon group has 1-5 carbon atoms (e.g., 1, 2, 3, 4, 5), preferably 2-4;

[0104] And / or: the oxygen-containing hydrocarbon group has 1-10 oxygen atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10), preferably 2-5;

[0105] And / or: The oxygen-containing hydrocarbon group is selected from hydrocarbon groups containing -C=O, -O-, -(C=O)- or -COO-.

[0106] As an optional embodiment of the present invention, when Y in the borate polymer is a short chain segment of a small molecule including groups such as hydrocarbon groups, ether bonds, carbonyl groups, carboxylic acid groups, and amino groups, i.e., of type Y1, the borate polymer is a general borate polymer, and its structure includes, but is not limited to, the following:

[0107]

[0108]

[0109] Where n, m and l are positive integers ≥ 1 (n, m and l can be 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 etc.), and l ≤ 20 (such as 20, 15, 10, 5 etc.), and the curve represents a half bond.

[0110] The weight-average molecular weight of the borate-like polymers of this invention is generally 9100–62300 Mwg / mol (e.g., 9500 Mwg / mol, 10000 Mwg / mol, 20000 Mwg / mol, 30000 Mwg / mol, 40000 Mwg / mol, 50000 Mwg / mol, 60000 Mwg / mol, 62000 Mwg / mol, etc.), the molecular weight distribution (PDI) is 1.37–1.61 (e.g., 1.38, 1.40, 1.42, 1.44, 1.46, 1.48, 1.50, 1.52, 1.54, 1.56, 1.58, 1.60, etc.), and the thermal decomposition temperature is 306–330℃ (e.g., 307℃, 310℃, 315℃, 320℃, 325℃, 329℃, etc.).

[0111] As an optional embodiment of the present invention, when Y is a long polymer chain segment and is a polyether segment of type Y2 or Y3 in the borate polymer, the borate polymer is a polyether-based borate polymer, and its structure includes, but is not limited to, the following:

[0112]

[0113]

[0114] Where n, x, m and y are positive integers ≥1 (n, x, m and y can be 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 etc.), and the curve represents a half bond.

[0115] In the above technical solution, the advantages of polyether-based borate polymers are: firstly, as a highly flexible polymer, polyether copolymerization with rigid borate units can improve the flexibility of borate polymers, improve the interfacial contact between the polymer and electrodes when used as a polymer electrolyte and / or separator, reduce interfacial impedance, and prevent the battery from failing to charge and discharge normally due to excessive internal resistance; secondly, the ether bond with Li + It has coordination properties and can dissociate and recoordinate with new Li as the molecular chain moves. + Li + Transport occurs during continuous coordination and dissociation, thereby improving the lithium-ion conductivity of the polymer electrolyte and / or membrane.

[0116] The weight-average molecular weight of the polyether borate polymers of this invention is 11200–260000 Mwg / mol (e.g., 11500 Mwg / mol, 20000 Mwg / mol, 40000 Mwg / mol, 60000 Mwg / mol, 80000 Mwg / mol, 100000 Mwg / mol, 150000 Mwg / mol, 200000 Mwg / mol, 2500 Mwg / mol). The molecular weight distribution (PDI) is 1.36–1.54 (e.g., 1.37, 1.39, 1.41, 1.43, 1.45, 1.47, 1.49, 1.51, 1.53, etc.), and the thermal decomposition temperature is 234–259℃ (e.g., 235℃, 237℃, 239℃, 241℃, 243℃, 245℃, 247℃, 249℃, 251℃, 253℃, 257℃, etc.).

[0117] As an optional embodiment of the present invention, when Y is a long polymer chain segment and is a polyester chain segment of type Y4 or Y5 in the borate polymer, the borate polymer is a polyester borate polymer, and its structure includes, but is not limited to, the following:

[0118]

[0119]

[0120] Where n, x, and m are positive integers ≥ 1 (n, x, and m can be 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.), and the curve represents a half bond.

[0121] In the above technical solution, the advantages of polyester-based borate polymers are: firstly, polyester, as a flexible polymer, copolymerizing with rigid borate units can improve the flexibility of borate polymers, improve the interfacial contact with electrodes when used as polymer electrolytes and / or separators, reduce interfacial impedance, and prevent the battery from failing to charge and discharge normally due to excessive internal resistance; secondly, ester bonds and Li+ It has coordination properties and can dissociate and recoordinate with new Li as the molecular chain moves. + Li + Transport occurs during continuous coordination and dissociation, thereby improving the lithium-ion conductivity of polymer electrolytes and / or membranes; furthermore, polyesters have a higher oxidation potential than polyethers, which can improve the electrochemical stability window of borate-type polymer electrolytes and / or membranes.

[0122] The weight-average molecular weight of the polyester borate polymers of this invention is 90,800–500,000 Mwg / mol (e.g., 10,000 Mwg / mol, 50,000 Mwg / mol, 100,000 Mwg / mol, 150,000 Mwg / mol, 200,000 Mwg / mol, 250,000 Mwg / mol, 300,000 Mwg / mol, 350,000 Mwg / mol, 400,000 Mwg / mol). / mol, 450000 Mwg / mol, etc.), with a molecular weight distribution PDI of 1.37 to 1.60 (e.g., 1.38, 1.40, 1.42, 1.44, 1.46, 1.48, 1.50, 1.52, 1.54, 1.56, 1.58, etc.), and a thermal decomposition temperature of 246 to 265℃ (e.g., 247℃, 249℃, 251℃, 253℃, 255℃, 257℃, 259℃, 261℃, 263℃, etc.).

[0123] As an optional embodiment of the present invention, when Y is a long polymer chain segment and is a polycarbonate segment of type Y6 in the borate polymer, the borate polymer is a polycarbonate-based borate polymer, and its structure includes, but is not limited to, the following:

[0124]

[0125] Where n, x, and m are positive integers ≥ 1 (n, x, and m can be 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.); the curve represents a half bond.

[0126] In the above technical solutions, the advantage of polycarbonate-based borate polymers is that, when used as polymer electrolytes, in addition to the carbonate groups being able to react with Li... + Coordination, promoting Li + In addition to improving lithium-ion conductivity, polycarbonate also has a very high oxidation potential, which can improve the electrochemical stability window of borate polymer electrolytes and / or membranes.

[0127] The weight-average molecular weight of the polycarbonate-based borate polymers of this invention is 68,000–243,000 Mwg / mol (e.g., 70,000 Mwg / mol, 100,000 Mwg / mol, 130,000 Mwg / mol, 150,000 Mwg / mol, 170,000 Mwg / mol, 190,000 Mwg / mol, 210,000 Mwg / mol). (e.g., 230,000 Mwg / mol), molecular weight distribution PDI is 1.54–1.68 (e.g., 1.55, 1.57, 1.59, 1.61, 1.63, 1.65, 1.67, etc.), thermal decomposition temperature is 344–378℃ (e.g., 345℃, 347℃, 349℃, 351℃, 355℃, 360℃, 365℃, 370℃, 375℃, 377℃, etc.).

[0128] As an optional embodiment of the present invention, when Y is a long polymer chain segment and is a polyamide segment of type Y7 in the borate polymer, the borate polymer is a polyamide-based borate polymer, and its structure includes, but is not limited to, the following:

[0129]

[0130] Any of the following, where m, n and x are positive integers ≥ 1 (m, n and x can be such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.); the curve represents a half bond.

[0131] In the above technical solutions, the advantages of polyamide-based borate polymers are: firstly, polyamides have good mechanical properties and high heat resistance, and after copolymerization with borate units, they can form high-heat-resistant polymer electrolytes and / or membranes with excellent mechanical properties; secondly, the amide bond and Li + It has coordination properties and can dissociate and recoordinate with new Li as the molecular chain moves. + Li + Transport occurs during continuous coordination and dissociation, thereby improving the lithium-ion conductivity of polymer electrolytes and / or membranes; furthermore, polyamides have a higher oxidation potential than polyethers, polyesters, etc., which can improve the electrochemical stability window of borate-type polymer electrolytes and / or membranes.

[0132] The polyamide borate polymers of this invention have a weight-average molecular weight of 61,000–250,000 Mwg / mol (e.g., 62,000 Mwg / mol, 65,000 Mwg / mol, 70,000 Mwg / mol, 100,000 Mwg / mol, 150,000 Mwg / mol, 200,000 Mwg / mol, 220,000 Mwg / mol, 240,000 Mwg / mol). The molecular weight distribution (PDI) is 1.39–1.48 (e.g., 1.40, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, etc.), and the thermal decomposition temperature is 325–349℃ (e.g., 326℃, 328℃, 330℃, 332℃, 334℃, 336℃, 338℃, 340℃, 342℃, 344℃, 346℃, 348℃, etc.).

[0133] According to a second aspect of the present invention, a method for preparing the above-described borate polymer, wherein the borate polymer is synthesized by copolymerization, and the copolymerization method includes three types, wherein...

[0134] The first copolymerization is as follows: the first substance containing Y undergoes a dehydration condensation reaction with the boric acid and the inorganic salt containing M required for the formation of X, to generate a borate-type polymer containing a borate structure, as shown in Formula I:

[0135]

[0136] The specific reaction formula is shown below:

[0137]

[0138] The second type of copolymerization involves a dehydration condensation reaction between the first substance containing Y and the borate containing X and the inorganic salt containing M, resulting in a borate-type polymer linked by borate groups, as shown in Formula II.

[0139]

[0140] The specific reaction formula is shown below:

[0141]

[0142] The third type of copolymerization involves a dehydration condensation reaction between the second Y-containing substance and the X-containing borate to generate a borate-type polymer linked by borates, as shown in Formula III.

[0143]

[0144] The specific reaction formula is shown below:

[0145]

[0146] In this context, R1 and R2 are each independently selected from hydrocarbon groups, halogenated hydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups, or amine-containing hydrocarbon groups. M is selected from Li and Na, and W is selected from O and NR. R is a hydrogen atom or an alkyl group, and m and n are both positive integers ≥1 (m and n can be such as 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc.). The curve represents a half bond.

[0147] In various copolymers, the first Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows:

[0148] In this case, N1 is independently selected from hydroxyl or carboxyl groups;

[0149] The first Y-containing substance is preferably a Y-containing small molecule or Y-containing polymer having two hydroxyl groups, two carboxyl groups, or one hydroxyl group and one carboxyl group at each end;

[0150] The second Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows:

[0151] N2-Y-N2, wherein each N2 group is independently selected from hydroxyl, carboxyl, or amino groups;

[0152] The second Y-containing substance is preferably a Y-containing small molecule or Y-containing polymer with a single hydroxyl group, a single carboxyl group or a single amine group at both ends;

[0153] The X-containing borate is a cyclic polymeric borate with borate groups at both ends, and is synthesized from boric acid, an inorganic salt containing M, and an organic compound containing hydroxyl or carboxyl groups.

[0154] The method for preparing borate-type polymers of this invention is simple, easy to implement, and uses inexpensive raw materials, making it suitable for large-scale production. Whether in copolymerization or the synthesis of X-containing borates, the inorganic salt containing M is either an inorganic lithium salt or an inorganic sodium salt. The inorganic lithium salt is typically, but not limited to, lithium hydroxide, lithium carbonate, etc. The inorganic sodium salt is typically, but not limited to, sodium hydroxide, sodium carbonate, etc. The first substance containing Y can typically, but not limited to, be a small molecule such as diglycerol; it can also typically, but not limited to, be modified small molecule substances such as butanediol derivatives, diglycerol derivatives, hexamethylenediamine derivatives, etc.

[0155] The first Y-containing substance can also be typically and non-limitingly selected from modified polymers such as polyethylene glycol (e.g., PEG200, PEG300, PEG400, PEG600, PEG1000, PEG2000) derivatives, polypropylene glycol (e.g., PPG200, PPG300, PPG400, PPG600, PPG1000) derivatives, polyethylene glycol / polypropylene glycol copolymer (e.g., PEG / PPG-17 / 6) derivatives, polyethylene succinate derivatives, polycaprolactone derivatives, polyvalerol derivatives, polypropylene carbonate derivatives, poly(hexamethylene terephthalamide) derivatives, and poly(diphenyl ether adipamide) diamine derivatives.

[0156] The second Y-containing substance can typically, but not exclusively, be selected from small molecule substances such as succinic acid and hexanediol. It can also typically, but not exclusively, be selected from high molecular weight polymers such as polyethylene glycol (e.g., PEG200, PEG300, PEG400, PEG600, PEG1000, PEG2000), polypropylene glycol (e.g., PPG200, PPG300, PPG400, PPG600, PPG1000), polyethylene glycol / polypropylene glycol copolymers (e.g., PEG / PPG-17 / 6), polyethylene succinate, polycaprolactone, polyvalerol, polypropylene carbonate, poly(hexamethylene terephthalamide), and poly(diphenyl ether adipamide).

[0157] Furthermore, some of the first Y-containing substances can be obtained by chemically modifying some of the second Y-containing substances, thus becoming derivatives of the second Y-containing substances. The chemical modification includes: causing the terminal hydroxyl, terminal carboxyl, or terminal amino groups of the second Y-containing substance to react chemically to generate a first Y-containing substance with two hydroxyl groups, two carboxyl groups, or one hydroxyl group and one carboxyl group at both ends. The specific modification process and number of modifications are not particularly limited, as long as the aforementioned requirements are met. Typical chemical reactions include a series of reactions one and a series of reactions two:

[0158] The first series of reactions includes: initiating ring-opening of a cyclic ether molecule through the hydroxyl, carboxyl, or amino groups at both ends of a second substance containing Y, yielding a first substance containing Y with two hydroxyl groups at each end (referred to as first substance containing Y 1 for ease of description below); then, the primary alcohol -CH2OH in first substance containing Y 1 can be directly oxidized by acidic potassium permanganate to yield first substance containing Y 2 with one hydroxyl group and one carboxyl group at each end, as shown in the following reaction formula:

[0159] (1)

[0160] (2)

[0161] In the reaction formula, A is a segment of a small molecule, polyether, polyester, polycarbonate, or polyamide; B is the part remaining after removing the active hydrogen from a terminal hydroxyl group, carboxyl group, or amino group; D is a hydrocarbon group or a halohydrocarbon; and the second substance containing Y is composed of A, B, and active hydrogen.

[0162] Cyclic ether molecules capable of this reaction include glycidyl, 2-hydroxymethyloxetane, tetrahydrofurfuryl alcohol, and glycerol formaldehyde, with the following structural formulas:

[0163]

[0164] The second series of reactions includes: esterification of the second Y-containing substance with 2,2-dimethylolpropionic acid via the direct reaction of the terminal hydroxyl groups of the second Y-containing substance to obtain the first Y-containing substance 3, which has dihydroxyl groups at both ends; then, the first Y-containing substance 3 can further react with potassium permanganate to oxidize the dihydroxyl groups to dicarboxyl groups, to obtain the first Y-containing substance 4, as shown in the following reaction formula:

[0165] (1)

[0166] (2)

[0167] In the reaction formula, A is a segment of a small molecule, polyether, polyester, polycarbonate, or polyamide; D is a hydrocarbon group or a halogenated hydrocarbon; and the second substance containing Y is composed of A and two terminal hydroxyl groups.

[0168] 2,2-Dimethylolpropionic acid can be replaced by 2,2-dimethylolbutyric acid and malic acid, and the specific structural formulas of the three are as follows:

[0169]

[0170] In reaction series one and / or reaction series two, the polyether segments can be obtained by ring-opening polymerization of epoxy monomers initiated by diols, diacids, or diamines. The polyester segments can be obtained by ring-opening polymerization of cyclic ester monomers initiated by diols, dicarboxylic acids, or diamines; or by polycondensation reaction of dicarboxylic acid monomers and diol monomers. The polycarbonate segments can be obtained by ring-opening polymerization of cyclic carbonate monomers initiated by diols, diacids, or diamines. The polyamide segments can be obtained by polycondensation reaction of diamines and dicarboxylic acids. The diols used typically include, but are not limited to, ethylene glycol, 1,3-propanediol, and 1,6-hexanediol; the diacids typically include, but are not limited to, oxalic acid, succinic acid, and adipic acid; the diamines typically include, but are not limited to, ethylenediamine and hexamethylenediamine; the epoxy monomers typically include, but are not limited to, ethylene oxide, propylene oxide, and 1,3-dioxolane; the cyclic ester monomers typically include, but are not limited to, lactide, δ-valerol, and ε-caprolactone; and the cyclic carbonate monomers typically include, but are not limited to, ethylene carbonate and propylene carbonate. These monomers can be homopolymerized or copolymerized.

[0171] As an optional embodiment of the present invention, the organic compound is at least one selected from tartaric acid, pentaerythritol, diglycerol, di(trimethylolpropane) and ethylenediaminetetraacetic acid.

[0172] In the above technical solution, the structural formula of tartaric acid is: The structural formula of pentaerythritol is: The structural formula of diglycerol is: The structural formula of bis(trimethylolpropane) is:

[0173] The above raw materials can react with boric acid and inorganic salts containing M to synthesize borates containing X, i.e., cyclic polymeric borates with borate groups at both ends. The reaction formulas are as follows:

[0174]

[0175]

[0176] M is selected from either Li or Na. For ease of description, the polymer borates obtained from the above reaction are named tartrate borate, pentaerythritol borate, dipolyglycerol borate, and di(trimethylolpropane) borate, respectively, depending on the raw materials.

[0177] Thirdly, the present invention provides an electrolyte comprising the above-mentioned borate polymer.

[0178] As an optional embodiment of the present invention, the electrolyte is a single-ion conductor polymer electrolyte.

[0179] The electrolyte of this invention contains a borate-type single-ion conductor polymer, which has superior performance compared to dual-ion conductor polymer electrolytes. Compared to polymer electrolytes that are composited with fluoroborates through physical methods, the borate in the electrolyte of this invention is not a small molecule salt but a polymer, and it is a single-ion conductor type. This restricts the movement of anions, effectively preventing the accumulation of anions that do not react with the electrode at the electrode, which would cause concentration polarization, increased battery internal resistance, and reduced energy efficiency. Moreover, it only allows cations such as lithium ions or sodium ions to migrate, greatly increasing the lithium ion transference number or sodium ion transference number, resulting in higher lithium ion conductivity or sodium ion conductivity.

[0180] As an optional embodiment of the present invention, the single-ion conductor polymer electrolyte is an all-solid polymer electrolyte or a gel polymer electrolyte, with a cation transference number > 0.9 (such as 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc.), and the cation is either lithium ion or sodium ion.

[0181] In the above technical solution, the all-solid-state polymer electrolyte comprises 100 wt% of the aforementioned borate polymer. Depending on the different cations in the borate polymer, it can be an all-solid-state lithium-ion conductor polymer electrolyte or an all-solid-state sodium-ion conductor polymer electrolyte. Regardless of whether it is lithium-ion or sodium-ion, the ionic conductivity of the all-solid-state polymer electrolyte is ≥5*10⁻⁶. -6 The S / cm ratio and cation transference number > 0.9 are higher than those of traditional all-solid polymer electrolytes.

[0182] The gel polymer electrolyte comprises the aforementioned borate polymer and an organic solvent. Depending on the cation in the borate polymer, it can be a gel lithium-ion conductor polymer electrolyte or a gel sodium-ion conductor polymer electrolyte. The organic solvent includes one or more of the following: acetonitrile, succinic anion, adiponitrile, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate, propyl acetate, 1,4-dioxane, 1,4-butyrolactone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, sulfolane, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and dipropyl carbonate. The gel polymer electrolyte, regardless of whether the cation in its borate polymer is lithium or sodium, has a cation mobility >0.9; a liquid absorption rate of 1%-1000%, preferably 1%-500%, more preferably 1%-300%; and an ionic conductivity ≥1*102 -5 S / cm, preferably, ionic conductivity ≥1*10 -4 S / cm. Compared to all-solid polymer electrolytes, it has higher ionic conductivity due to the introduction of organic solvents.

[0183] As an optional embodiment of the present invention, the all-solid polymer electrolyte membrane is prepared by: preparing a solution of a borate polymer, coating the solution into a film, and drying it to obtain the all-solid polymer electrolyte membrane. This polymer electrolyte membrane exhibits good mechanical properties and thermodynamic stability.

[0184] As an optional embodiment of the present invention, the gel polymer electrolyte membrane is prepared by: preparing a solution of a borate polymer, coating the solution into a film, drying it, and then absorbing an organic solvent to obtain the gel polymer electrolyte membrane. This gel polymer electrolyte membrane exhibits excellent mechanical properties and thermodynamic stability.

[0185] As an optional embodiment of the present invention, the above-mentioned borate polymer is dissolved in a good solvent to obtain a homogeneous polymer solution. The good solvent is selected from solvents capable of dissolving borate polymers, such as N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and acetonitrile.

[0186] As an optional embodiment of the present invention, the polymer solution is uniformly coated onto a substrate under low humidity conditions with a dew point of -40°C to -60°C, and a dry film is obtained after the solvent has completely evaporated. Coating under low humidity conditions with a dew point of -40°C to -60°C can prevent the polymer from hydrolyzing.

[0187] As an optional embodiment of the present invention, there are two ways to absorb organic solvent after drying: one way is to immerse the dried film in organic solvent, and the other way is to spray organic solvent onto the dried film, wherein the mass ratio of borate polymer to organic solvent is 1:0.1-10 (e.g., 1:0.5, 1:1, 1:2, 1:4, 1:6, 1:8, etc.).

[0188] Fourthly, the present invention provides a diaphragm comprising the above-described borate polymer.

[0189] As an optional embodiment of the present invention, the diaphragm is a single-ion conductor polymer diaphragm.

[0190] The separator of the present invention contains a borate-type single-ion conductor polymer, which has superior performance compared to a dual-ion conductor polymer separator. Compared to polymer separators that are composited with fluoroborates by physical methods, the borate in the separator of the present invention is not a small molecule salt but a polymer, and it is a single-ion conductor type. This restricts the movement of anions, effectively avoiding the accumulation of anions that do not react with the electrodes at the electrodes, which would cause concentration polarization, increased battery internal resistance, and reduced energy efficiency. Moreover, it only allows cations such as lithium ions or sodium ions to migrate, greatly increasing the lithium ion transference number or sodium ion transference number, and thus having higher lithium ion conductivity or sodium ion conductivity.

[0191] As an optional embodiment of the present invention, the single-ion conductor polymer membrane is an all-solid polymer membrane or a gel polymer membrane, with a cation transference number > 0.9 (such as 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc.), and the cation is either lithium ion or sodium ion.

[0192] In the above technical solution, the all-solid polymer membrane comprises 100 wt% of the aforementioned borate polymer. Depending on the different cations in the borate polymer, it can be an all-solid lithium-ion conductor polymer membrane or an all-solid sodium-ion conductor polymer membrane. Regardless of whether it is lithium-ion or sodium-ion, the ionic conductivity of the all-solid polymer membrane is ≥5*10⁻⁶. -6 S / cm and cation transfer number > 0.9 are higher than those of traditional all-solid polymer membranes.

[0193] The gel polymer membrane comprises the aforementioned borate polymer and an organic solvent. Depending on the cation in the borate polymer, it can be a gel lithium-ion conductor polymer membrane or a gel sodium-ion conductor polymer membrane. The organic solvent includes one or more of acetonitrile, succinic anion, adiponitrile, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate, propyl acetate, 1,4-dioxane, 1,4-butyrolactone, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, sulfolane, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and dipropyl carbonate. The gel polymer membrane, regardless of whether the cation in its borate polymer is lithium or sodium, has a cation mobility >0.9; a liquid absorption rate of 1%-1000%, preferably 1%-500%, more preferably 1%-300%; and an ionic conductivity ≥1*102 - 5 S / cm, preferably, ionic conductivity ≥1*10 -4 S / cm. Compared to all-solid polymer membranes, it has higher ionic conductivity due to the introduction of organic solvents.

[0194] As an optional embodiment of the present invention, the all-solid polymer membrane is prepared by: preparing a borate polymer into a solution, coating the solution into a film, and drying it to obtain the all-solid polymer membrane. This polymer membrane exhibits good mechanical properties and thermodynamic stability.

[0195] As an optional embodiment of the present invention, the gel polymer membrane is prepared by: preparing a solution of a borate polymer, coating the solution into a film, drying it, and then absorbing an organic solvent to obtain the gel polymer membrane. This gel polymer membrane exhibits excellent mechanical properties and thermodynamic stability.

[0196] As an optional embodiment of the present invention, the above-mentioned borate polymer is dissolved in a good solvent to obtain a homogeneous polymer solution. The good solvent is selected from solvents capable of dissolving borate polymers, such as N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and acetonitrile.

[0197] As an optional embodiment of the present invention, the polymer solution is uniformly coated onto a substrate under low humidity conditions with a dew point of -40°C to -60°C, and a dry film is obtained after the solvent has completely evaporated. Coating under low humidity conditions with a dew point of -40°C to -60°C can prevent the polymer from hydrolyzing.

[0198] As an optional embodiment of the present invention, there are two ways to absorb organic solvent after drying: one way is to immerse the dried film in organic solvent, and the other way is to spray organic solvent onto the dried film, wherein the mass ratio of borate polymer to organic solvent is 1:0.1-10 (e.g., 1:0.5, 1:1, 1:2, 1:4, 1:6, 1:8, etc.).

[0199] Fifthly, the present invention provides a battery, which is one of a lithium-ion battery, a sodium-ion battery, a lithium metal battery, or a sodium metal battery, and the battery includes the above-mentioned borate polymer.

[0200] The battery of the present invention has low internal resistance, high energy efficiency, good rate performance, good safety, and long cycle life.

[0201] As an optional embodiment of the present invention, the lithium-ion battery or sodium-ion battery is a single-ion conductor polymer battery.

[0202] As an optional embodiment of the present invention, the single-ion conductor polymer battery includes a positive electrode plate, a negative electrode plate, an separator, and an electrolyte; wherein the positive electrode plate contains the borate polymer; and / or, the negative electrode plate contains the borate polymer; and / or, the separator contains the borate polymer; and / or, the electrolyte contains the borate polymer.

[0203] In the above technical solution, the single-ion conductor polymer battery may contain the borate polymer in a single positive electrode plate, a single negative electrode plate, a single separator, or a single electrolyte. Of course, in the single-ion polymer battery, the borate polymer may also exist simultaneously in the positive and negative electrode plates, or in the positive electrode plate and separator, or in the negative electrode plate and separator, or in the positive electrode plate and electrolyte, or in the negative electrode plate and electrolyte, or in the electrolyte and separator, or in both positive and negative electrode plates and electrolyte, or in the positive electrode plate, separator, and electrolyte, or in the negative electrode plate, separator, and electrolyte, or in both positive and negative electrode plates and separator, or in the positive electrode plate, negative electrode plate, electrolyte, and separator. There are two ways in which the borate polymer is contained in the separator and / or electrolyte: one is to use the borate polymer to form an all-solid membrane as the separator and / or electrolyte directly; the other is to use the borate polymer to form a gel membrane as the separator and / or electrolyte directly. When the electrolyte contains the borate polymer but the separator does not contain the borate polymer, a PE membrane can be used as the separator.

[0204] The borate polymers of this invention contained in the positive and negative electrode plates are used as additives to fill the pores of the electrode sheets, enhance ion conduction, and reduce the internal resistance of the cell. The specific process is as follows: For all-solid-state battery systems, the borate polymer is mixed with the positive (negative) active material, conductive agent, and binder to form a slurry, which is then coated onto the current collector and dried to obtain the positive (negative) electrode plate. For gel-state (also known as semi-solid-state) battery systems, the borate polymer is mixed with the positive (negative) active material, conductive agent, and binder to form a slurry, which is then coated onto the current collector and dried to obtain the positive (negative) electrode plate. This slurry is then soaked or sprayed with an organic solvent to prepare a gel-state positive (negative) electrode plate.

[0205] All raw materials used in this invention are commercially available.

[0206] The present invention will now be described in further detail with reference to specific embodiments, application examples, and comparative application examples.

[0207] Example 1

[0208] In this embodiment, a general borate-like polymer (X1-Y101) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0209] n is a positive integer ≥ 1, and the curve represents a half bond.

[0210] Its preparation methods include:

[0211] Add 62g of boric acid and 300g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask equipped with a magnetic stir bar, then add 500g of diglycerol aqueous solution (solid content 33%). The molar ratio of boric acid, lithium hydroxide and diglycerol is 1:1:1. Stir thoroughly to mix evenly, remove solvent water by vacuum distillation, and dry under vacuum at 100℃ for 24h to finally obtain a white solid, which is a general borate-type polymer (X1-Y101).

[0212] Example 2

[0213] In this embodiment, a general borate-like polymer (X1-Y102) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0214] n is a positive integer ≥ 1, and the curve represents a half bond.

[0215] Its preparation methods include:

[0216] (1) Add 45g butanediol, 74g glycidyl and 200mL solvent 1,4-dioxane to a round-bottom flask equipped with a magnetic ball. The molar ratio of butanediol to glycidyl is 1:2. React at 90℃ for 10h. Remove the solvent by vacuum distillation to obtain a butanediol derivative with dihydroxyl groups at both ends.

[0217] (2) Add 25g of boric acid and 120g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 220g of the aqueous solution of butanediol derivative synthesized in step (1) (solid content 30%). The molar ratio of boric acid, lithium hydroxide and butanediol derivative is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a general borate-type polymer (X1-Y102).

[0218] Example 3

[0219] In this embodiment, a general borate-like polymer (X2-Y103) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0220] n is a positive integer ≥ 1, and the curve represents a half bond.

[0221] Its preparation methods include:

[0222] (1) Dissolve 83g of diglycerol in 150mL of water in a round-bottom flask containing a magnetic ball, then add 100g of acidic potassium permanganate aqueous solution (solid content 5%), react for 12h, extract with dichloromethane, collect the organic phase, dry with magnesium sulfate, filter, and distill the organic phase under reduced pressure to obtain a diglycerol derivative with a carboxyl group and a hydroxyl group at each end.

[0223] (2) Add 25g of boric acid and 120g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 200g of the diglyceride derivative aqueous solution (solid content 40%) synthesized in step (1). The molar ratio of boric acid, lithium hydroxide and diglyceride derivative is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a general borate-type polymer (X2-Y103).

[0224] Example 4

[0225] In this embodiment, a general borate-like polymer (X1-Y104) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0226] n is a positive integer ≥ 1, and the curve represents a half bond.

[0227] Its preparation methods include:

[0228] (1) Add 58g hexamethylenediamine, 74g glycidyl ether and 200mL acetonitrile to a round-bottom flask equipped with a magnetic flask. The molar ratio of hexamethylenediamine to glycidyl ether is 1:2. React at 80℃ for 10h. Remove the solvent by vacuum distillation to obtain a hexamethylenediamine derivative with dihydroxyl groups at both ends.

[0229] (2) Add 28g of boric acid and 135g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 298g of the aqueous solution of the hexamethylenediamine derivative synthesized in step (1) (solid content 40%). The molar ratio of boric acid, lithium hydroxide and the product of step (1) is 1:1:1. Stir and mix thoroughly, remove the solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a general borate-type polymer (X1-Y104).

[0230] Example 5

[0231] In this embodiment, a general borate-like polymer (X6-Y105) was synthesized through a third copolymerization method, and its structural formula is as follows:

[0232] n is a positive integer ≥ 1, and the curve represents a half bond.

[0233] Its preparation methods include:

[0234] (1) Add 43g boric acid, 90g tartaric acid, and 12g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 7:6:5. Then add 300mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0235] (2) Dissolve 110g of tartrate borate prepared in step (1) completely in NMP, and add 8.8g of butanediamine at the same time. The molar ratio of tartrate borate to butanediamine is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation to obtain the product, which is a general borate-type polymer (X6-Y105) copolymerized from tartrate borate and butanediamine.

[0236] Example 6

[0237] In this embodiment, a general borate-like polymer (X9-Y106) was synthesized through a third copolymerization method, and its structural formula is as follows:

[0238] n is a positive integer ≥ 1, and the curve represents a half bond.

[0239] Its preparation methods include:

[0240] (1) Add 62g boric acid, 123g pentaerythritol, and 19g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, pentaerythritol, and lithium hydroxide is 10:9:8. Then add 300mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is pentaerythritol borate.

[0241] (2) Dissolve 69g of pentaerythritol borate prepared in step (1) completely in 230mL of NMP, and add 6g of hexanediol at the same time. The molar ratio of pentaerythritol borate to hexanediol is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation to obtain the product, which is a general borate-type polymer (X9-Y106) copolymerized from pentaerythritol borate and hexanediol.

[0242] Example 7

[0243] In this embodiment, a polyether-based borate polymer (X1-Y201) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0244] n is a positive integer ≥ 1, and the curve represents a half bond.

[0245] Its preparation methods include:

[0246] (1) Add 80g polyethylene glycol PEG400, 30g glycidyl ether and 200mL solvent acetonitrile to a round-bottom flask equipped with a magnetic ball. The molar ratio of PEG400 to glycidyl ether is 1:2. React at 80℃ for 10h. Remove the solvent by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0247] (2) Add 12.4g of boric acid and 60g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 220g of aqueous solution of the product in step (1) (solid content 50%). The molar ratio of boric acid, lithium hydroxide and PEG in step (1) is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and vacuum dry at 100℃ for 24h to finally obtain a white solid, which is a polyether borate polymer (X1-Y201).

[0248] Example 8

[0249] In this embodiment, a polyether-based borate polymer (X2-Y202) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0250] n is a positive integer ≥ 1, and the curve represents a half bond.

[0251] Its preparation methods include:

[0252] (1) Add 120g of polypropylene glycol PPG600, 30g of glycidyl ether and 300mL of solvent acetonitrile to a round-bottom flask equipped with a magnetic ball. The molar ratio of PPG600 to glycidyl ether is 1:2. React at 80℃ for 10h. Remove the solvent by vacuum distillation to obtain a PPG derivative with dihydroxyl groups at both ends.

[0253] (2) Dissolve 150g of the product synthesized in step (1) in water, add 100g of acidic potassium permanganate aqueous solution (solid content 5%), react for 12h, extract with dichloromethane, collect the organic phase, dry with magnesium sulfate, filter, and distill the organic phase under reduced pressure to obtain PPG derivatives with a carboxyl group and a hydroxyl group at each end.

[0254] (3) Add 9.3g of boric acid and 3.6g of lithium hydroxide aqueous solution to a round-bottom flask equipped with a magnetic flask, then add 390g of the aqueous solution of the product synthesized in step (2) (solid content 30%). The molar ratio of boric acid, lithium hydroxide and product of step (2) is 1:1:1. Stir thoroughly to mix evenly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C.

[0255] After 24 hours, a white solid was finally obtained, which was a polyether borate polymer (X2-Y202).

[0256] Example 9

[0257] In this embodiment, a polyether-based borate polymer (X1-Y301) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0258] n is a positive integer ≥ 1, and the curve represents a half bond.

[0259] Its preparation methods include:

[0260] (1) Add 110g of polyethylene glycol / polypropylene glycol copolymer (PEG / PPG-17 / 6, M) to a round-bottom flask containing a magnetic flask. n Approximately 1100 g of glycidyl ether and 15 g of glycidyl ether were reacted with 250 mL of acetonitrile solvent at a molar ratio of 1:2. The reaction was carried out at 80 °C for 10 h. The solvent was removed by vacuum distillation to obtain a PEG / PPG copolymer derivative with dihydroxyl groups at both ends.

[0261] (2) Add 5g of boric acid and 1.9g of lithium hydroxide aqueous solution to a round-bottom flask containing a magnetic ball, and then add 100g of aqueous solution of the product of step (1). The molar ratio of boric acid, lithium hydroxide and product of step (1) is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a polyether borate polymer (X1-Y301).

[0262] Example 10

[0263] In this embodiment, a polyether-based borate polymer (X3-Y203) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0264] n is a positive integer ≥ 1, and the curve represents a half bond.

[0265] Its preparation methods include:

[0266] (1) Add 50g of polyethylene glycol PEG200, 67g of 2,2-dimethylolpropionic acid and 100mL of dry solvent dioxane to a round-bottom flask equipped with a magnetic flask. The molar ratio of PEG200 and 2,2-dimethylolpropionic acid is 1:2. At the same time, add 2% of catalyst 4-dimethylaminopyridine (DMAP) and 2% of N,N'-dicyclohexylcarbodiimide (DCC) (based on the total weight of PEG200 and 2,2-dimethylolpropionic acid). React at 80℃ for 12h. After stopping the reaction, add a small amount of water, filter to remove insoluble matter, and remove solvent by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0267] (2) Add 12.4g of boric acid and 60g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 216g of aqueous solution of the product of step (1) (solid content 40%). The molar ratio of boric acid, lithium hydroxide and product of step (1) is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a polyether borate polymer (X3-Y203).

[0268] Example 11

[0269] In this embodiment, a polyether-based borate polymer (X2-Y204) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0270] n is a positive integer ≥ 1, and the curve represents a half bond.

[0271] Its preparation methods include:

[0272] (1) 100g polyethylene glycol PEG300, 89g malic acid and 250mL dry solvent dioxane were added to a round-bottom flask equipped with a magnetic flask. The molar ratio of PEG300 to malic acid was 1:2. At the same time, 1% catalyst 4-dimethylaminopyridine (DMAP) and 2% N,N'-dicyclohexylcarbodiimide (DCC) (based on the total weight of PEG300 and malic acid) were added. The reaction was carried out at 80℃ for 12h. After the reaction was stopped, a small amount of water was added, the insoluble matter was removed by filtration, and the solvent was removed by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0273] (2) Add 18g of boric acid and 88g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 252g of aqueous solution of the product of step (1) (solid content 50%). The molar ratio of boric acid, lithium hydroxide and product of step (1) is 1:1:1. Stir and mix thoroughly, remove solvent water by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a polyether borate polymer (X2-Y204).

[0274] Example 12

[0275] In this embodiment, a polyether-based borate polymer (X5-Y205) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0276] n is a positive integer ≥ 1, and the curve represents a half bond.

[0277] Its preparation methods include:

[0278] (1) Add 100g of polyethylene glycol PEG400, 74g of 2,2-dimethylolbutyric acid, and... to a round-bottom flask containing a magnetic flask.

[0279] 250 mL of dry solvent dioxane, PEG400 and 2,2-dihydroxymethylbutyric acid were mixed in a molar ratio of 1:2. 1% of the catalyst 4-dimethylaminopyridine (DMAP) and 3% of N,N'-dicyclohexylcarbodiimide (DCC) (based on the total weight of PEG400 and 2,2-dihydroxymethylbutyric acid) were added. The mixture was reacted at 80 °C for 12 h. After the reaction was stopped, a small amount of water was added, the insoluble matter was removed by filtration, and the solvent was removed by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0280] (2) Dissolve 150g of the product from step (1) in 300mL of water, add 50g of acidic potassium permanganate aqueous solution (solid content 5%), react for 12h, extract with dichloromethane, collect the organic phase, dry with magnesium sulfate, filter, and distill the organic phase under reduced pressure to obtain a PEG derivative with dicarboxyl groups at both ends.

[0281] (3) Add 13g of boric acid and 65g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ingot, then add 314g of the aqueous solution of the product from step (2) (solid content 50%), boric acid, lithium hydroxide and step (2)

[0282] The molar ratio of the products was 1:1:1. After thorough mixing, the solvent water was removed by vacuum distillation, and the product was dried under vacuum at 100°C for 24 hours to obtain a white solid, which was a polyether borate polymer (X5-Y205).

[0283] Example 13

[0284] In this embodiment, a polyether-based borate polymer (X6-Y206) was synthesized via a third copolymerization method, and its structural formula is as follows:

[0285] n is a positive integer ≥ 1, and the curve represents a half bond.

[0286] Its preparation methods include:

[0287] (1) Add 37g boric acid, 83g tartaric acid, and 12g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 12:11:10. Then add 250mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0288] (2) Dissolve 76g of tartrate borate prepared in step (1) completely in 180mL of NMP, and add 24g of polypropylene glycol 600 (PPG600) at the same time. The molar ratio of tartrate borate to PPG600 is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is the polyether borate polymer (X6-Y206) copolymerized from tartrate borate and polypropylene glycol.

[0289] Example 14

[0290] In this embodiment, a polyether-based borate polymer (X8-Y207) was synthesized via a second copolymerization method, and its structural formula is as follows:

[0291] n is a positive integer ≥ 1, and the curve represents a half bond.

[0292] Its preparation methods include:

[0293] (1) Add 150g polyethylene glycol PEG1000, 23g glycidyl ether, and 200mL to a round-bottom flask containing a magnetic flask.

[0294] The solvent acetonitrile, PEG1000 and glycidyl were reacted in a molar ratio of 1:2 at 80°C for 10 h. The solvent was removed by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0295] (2) Add 39g boric acid, 84g tartaric acid, and 12g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 10:9:8. Then add 250mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0296] (3) Dissolve 80g of tartrate borate prepared in step (2) completely in 200mL of NMP, and add 61g of PEG derivative synthesized in step (1) and 12g of lithium carbonate. The molar ratio of tartrate borate, PEG derivative and lithium carbonate is 1:1:3. The reaction is carried out at 100℃ while the water is removed by vacuum distillation. The reaction is stopped when no liquid is distilled out. The excess lithium carbonate is removed by filtration, the filtrate is collected, and the solvent NMP is removed by rotary evaporation. The product is a polyether borate type polymer (X8-Y207) copolymerized from tartrate borate and polyethylene glycol derivative.

[0297] Example 15

[0298] In this embodiment, a polyether-based borate polymer (X11-Y208) was synthesized via a second copolymerization method, and its structural formula is as follows:

[0299]

[0300] n is a positive integer ≥ 1, and the curve represents a half bond.

[0301] Its preparation methods include:

[0302] (1) 100g of polyethylene glycol PEG2000, 14g of 2,2-dimethylolpropionic acid and dry solvent dioxane were added to a round-bottom flask equipped with a magnetic flask. The molar ratio of PEG2000 and 2,2-dimethylolpropionic acid was 1:2. At the same time, 1% of the catalyst 4-dimethylaminopyridine (DMAP) and 2% of N,N'-dicyclohexylcarbodiimide (DCC) were added (based on the total weight of PEG2000 and 2,2-dimethylolpropionic acid). The reaction was carried out at 80°C for 12h. After the reaction was stopped, a small amount of water was added, the insoluble matter was removed by filtration, and the solvent was removed by vacuum distillation to obtain a PEG derivative with dihydroxyl groups at both ends.

[0303] (2) Dissolve 100g of the product from step (1) in 150mL of water, add 50g of acidic potassium permanganate aqueous solution (solid content 5%), react for 12h, extract with dichloromethane, collect the organic phase, dry with magnesium sulfate, filter, and distill the organic phase under reduced pressure to obtain a PEG derivative with dicarboxyl groups at both ends.

[0304] (3) Add 47g boric acid, 179g bis(trimethylol)propane, and 16g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, bis(trimethylol)propane, and lithium hydroxide is 17:16:15. Then add 300mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is bis(trimethylol)propane borate.

[0305] (4) Take 150g of the bis(trimethylol)propane borate prepared in step (3) and completely dissolve it in 250mL of NMP. At the same time, add 81g of the product from step (2) and 10g of lithium carbonate. The molar ratio of bis(trimethylol)propane borate, the product from step (2) and lithium carbonate is 1:1:4. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Filter to remove excess lithium carbonate, collect the filtrate, and remove the solvent NMP by rotary evaporation. The product obtained is a polyether borate polymer (X11-Y208) copolymerized from bis(trimethylol)propane borate and polyethylene glycol derivative.

[0306] Example 16

[0307] In this embodiment, a polyester borate polymer (X1-Y401) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0308] n is a positive integer ≥ 1, and the curve represents a half bond.

[0309] Its preparation methods include:

[0310] (1) Add 118g of succinic acid and 68g of ethylene glycol to a round-bottom flask. The molar ratio of succinic acid to ethylene glycol is 1:1.1. Then add 0.4% tetrabutyl titanate (based on the total mass of ethylene glycol and succinic acid) as a catalyst. Vacuum the flask and react at 200℃ for 10h. After stopping the reaction, the product obtained is a hydroxyl-terminated polyethylene succinate derivative.

[0311] (2) Add 150g of the product of step (1), 13g of glycidyl ether and 200mL of dioxane solvent to a round-bottom flask containing a magnetic ball. The molar ratio of the product of step (1) to glycidyl ether is 1:2. React at 80℃ for 10h. Remove the solvent by vacuum distillation to obtain a poly(ethylene succinate) derivative with two hydroxyl groups at each end.

[0312] (3) Add 5g of boric acid and 25g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 150g of dioxane solution of the product of step (2). The molar ratio of boric acid, lithium hydroxide and product of step (2) is 1:1:1. Stir and mix thoroughly, remove solvent water and dioxane by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a polyester borate polymer (X1-Y401).

[0313] Example 17

[0314] In this embodiment, a polyester-based borate polymer (X4-Y501) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0315] n is a positive integer ≥ 1, and the curve represents a half bond.

[0316] Its preparation methods include:

[0317] (1) Add 2g of ethylene glycol and 147g of ε-caprolactone to a round-bottom flask. The molar ratio of ethylene glycol to ε-caprolactone is 1:1.

[0318] 40, then add 0.1% methanesulfonic acid (based on the total mass of ethylene glycol and ε-caprolactone) as a catalyst, react at 100℃ for 12 h, after stopping the reaction, dissolve the product in 250 mL of tetrahydrofuran (THF), add LiOH aqueous solution to neutralize to pH = 7, remove the solvent by rotary evaporation, continue to dissolve the solid product in THF, filter to remove insoluble matter, collect the filtrate, and dry to obtain the product, which is a polycaprolactone (PCL) derivative with terminal hydroxyl groups.

[0319] (2) Add 120g of the product from step (1), 7g of 2,2-dihydroxymethylpropionic acid and 150mL of dry solvent dioxane to a round-bottom flask equipped with a magnetic ball. The molar ratio of the product from step (1) and 2,2-dihydroxymethylpropionic acid is 1:2. At the same time, add 1% of the catalyst 4-dimethylaminopyridine (DMAP) and 2% of N,N'-dicyclohexylcarbodiimide (DCC) (based on the total mass of the product from step (1) and 2,2-dihydroxymethylpropionic acid). React at 80°C for 12h. After stopping the reaction, add a small amount of water, filter to remove insoluble matter, and remove the solvent by vacuum distillation to obtain a PCL derivative with dihydroxyl groups at both ends.

[0320] (3) Take 120g of the product from step (2) and dissolve it in 180mL of dioxane. Add 50g of acidic potassium permanganate aqueous solution (solid content 5%) and react for 12h. Extract with dichloromethane, collect the organic phase, dry with magnesium sulfate, filter, and distill the organic phase under reduced pressure to obtain a PCL derivative with dicarboxyl groups at both ends.

[0321] (4) Add 1.3g of boric acid and 6g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 250g of tetrahydrofuran solution of the product of step (3) (solid content 40%). The molar ratio of boric acid, lithium hydroxide and the product of step (3) is 1:1:1. Stir and mix thoroughly, remove solvent water and tetrahydrofuran by vacuum distillation, and dry under vacuum at 100°C for 24h to finally obtain a white solid, which is a polyester borate polymer (X4-Y501).

[0322] Example 18

[0323] In this embodiment, a polyester-borate polymer (X6-Y402) was synthesized through a third copolymerization method, and its structural formula is as follows:

[0324] n is a positive integer ≥ 1, and the curve represents a half bond.

[0325] Its preparation methods include:

[0326] (1) Add 118g of succinic acid and 65g of ethylene glycol to a round-bottom flask. The molar ratio of succinic acid to ethylene glycol is 1:1.

[0327] 1.05, then add 0.2% tetrabutyl titanate (based on the total mass of ethylene glycol and succinic acid) as a catalyst, vacuum the reaction, and react at 200℃ for 10h. After stopping the reaction, the product obtained is a hydroxyl-terminated polyethylene succinate derivative.

[0328] (2) Add 74g boric acid, 165g tartaric acid, and 24g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 12:11:10. Then add 350mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0329] (3) Take 56g of the tartrate borate prepared in step (2) and completely dissolve it in 500mL of NMP. At the same time, add 99g of the product from step (1). The molar ratio of tartrate borate to the product from step (1) is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is a polyester borate type polymer (X6-Y402) copolymerized from tartrate borate and polyethylene succinate derivative.

[0330] Example 19

[0331] In this embodiment, a polyester borate polymer (X7-Y403) was synthesized through a second copolymerization method, and its structural formula is as follows:

[0332] n is a positive integer ≥ 1, and the curve represents a half bond.

[0333] Its preparation methods include:

[0334] (1) Add 118g of succinic acid and 63g of ethylene glycol to a round-bottom flask. The molar ratio of succinic acid to ethylene glycol is 1:1.02. Then add 0.4% tetrabutyl titanate (based on the total mass of ethylene glycol and succinic acid) as a catalyst. Vacuum the flask and react at 200℃ for 10h. After stopping the reaction, the product obtained is a hydroxyl-terminated polyethylene succinate derivative.

[0335] (2) Add 122g of the product from step (1), 4g of malic acid and 200mL of dry solvent NMP to a round-bottom flask equipped with a magnetic ball. The molar ratio of the product from step (1) to malic acid is 1:2. At the same time, add 1% of the catalyst 4-dimethylaminopyridine (DMAP) and 2% of N,N'-dicyclohexylcarbodiimide (DCC) (based on the total mass of the product from step (1) and malic acid). React at 80°C for 12h. After stopping the reaction, add a small amount of water, filter to remove insoluble matter, and remove water by vacuum distillation at 80°C to obtain a poly(ethylene succinate) derivative NMP solution with a carboxyl group and a hydroxyl group at each end.

[0336] (3) Add 65g boric acid, 153g tartaric acid, and 24g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 52:51:50. Then add 400mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0337] (4) Take 100g of the tartrate borate prepared in step (3) and completely dissolve it in 200mL of NMP. At the same time, add 250g of the NMP solution (solid content 40%) of the poly(ethylene succinate) derivative synthesized in step (2). The molar ratio of tartrate borate to poly(ethylene succinate) derivative is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled off. Remove the solvent NMP by rotary evaporation. The product obtained is a polyester borate type polymer (X7-Y403) copolymerized from tartrate borate and poly(ethylene succinate) derivative.

[0338] Example 20

[0339] In this embodiment, a polyester borate polymer (X10-Y502) was synthesized through a third copolymerization method, and its structural formula is as follows:

[0340]

[0341] n is a positive integer ≥ 1, and the curve represents a half bond.

[0342] Its preparation methods include:

[0343] (1) Add 2.3g of 1,3-propanediol and 150g of δ-valerolactone to a round-bottom flask. The molar ratio of 1,3-propanediol to δ-valerolactone is 1:50. Then add 0.2% sulfuric acid (based on the total mass of 1,3-propanediol and δ-valerolactone) as a catalyst. React at 100℃ for 12h. After stopping the reaction, dissolve the product in tetrahydrofuran (THF) and add LiOH aqueous solution to neutralize to pH=7. Remove the solvent by rotary evaporation. Continue to dissolve the solid product in THF. Filter to remove insoluble matter, collect the filtrate, and dry to obtain the product, which is a polyvalerolactone (PVL) derivative with terminal hydroxyl groups.

[0344] (2) Add 68g boric acid, 174g diglycerol, and 24g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, diglycerol, and lithium hydroxide is 22:21:20. Add 300mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is diglycerol borate.

[0345] (3) Take 100g of the diglycerol borate prepared in step (2) and completely dissolve it in 200mL of NMP. At the same time, add 133g of the PVL derivative synthesized in step (1). The molar ratio of diglycerol borate to PVL derivative is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is a polyester borate polymer (X10-Y502) copolymerized from diglycerol borate and PVL derivative.

[0346] Example 21

[0347] In this embodiment, a polycarbonate-based borate polymer (X1-Y601) was synthesized through the first copolymerization method, and its structural formula is as follows:

[0348] n is a positive integer ≥ 1, and the curve represents a half bond.

[0349] Its preparation methods include:

[0350] (1) Add 3g of ethylene glycol and 102g of propylene carbonate to a round-bottom flask. The molar ratio of ethylene glycol to propylene carbonate is 1:20. Then add 0.2% sulfuric acid (based on the total mass of ethylene glycol and propylene carbonate) as a catalyst. React at 100℃ for 12h. After stopping the reaction, dissolve the product in N,N-dimethylformamide (DMF) and add LiOH aqueous solution to neutralize to pH=7. Remove the solvent by rotary evaporation. Continue to dissolve the solid product in DMF. Filter to remove insoluble matter, collect the filtrate, and dry to obtain a hydroxyl-terminated polypropylene carbonate derivative.

[0351] (2) Add 100g of the product from step (1), 7g of glycidyl ether and 150mL of solvent NMP to a round-bottom flask containing a magnetic ball. The molar ratio of polypropylene carbonate to glycidyl ether is 1:2. React at 80°C for 10h. Remove the solvent by vacuum distillation to obtain polypropylene carbonate derivatives with two hydroxyl groups at each end.

[0352] (3) Add 3g of boric acid and 23g of lithium hydroxide aqueous solution (solid content 5%) to a round-bottom flask containing a magnetic ball, and then add 250g of NMP solution of the product in step (2) (solid content 40%). The molar ratio of boric acid, lithium hydroxide and product in step (2) is 1:1:1. Stir and mix thoroughly, remove solvent water and NMP by vacuum distillation, and dry under vacuum at 120°C for 24h to finally obtain a light yellow solid, which is a polycarbonate borate type polymer (X1-Y601).

[0353] Example 22

[0354] In this embodiment, a polycarbonate-based borate polymer (X6-Y602) was synthesized via a third copolymerization method, and its structural formula is as follows:

[0355] n is a positive integer ≥ 1, and the curve represents a half bond.

[0356] Its preparation methods include:

[0357] (1) Add 1.9g of ethylene glycol and 153g of propylene carbonate to a round-bottom flask. The molar ratio of ethylene glycol to propylene carbonate is 1:50. Then add 0.25% sulfuric acid (based on the total mass of ethylene glycol and propylene carbonate) as a catalyst. React at 100℃ for 12h. After stopping the reaction, dissolve the product in N,N-dimethylformamide (DMF) and add LiOH aqueous solution to neutralize to pH=7. Remove the solvent by rotary evaporation. Continue to dissolve the solid product in DMF. Filter to remove insoluble matter, collect the filtrate, and dry to obtain a hydroxyl-terminated polypropylene carbonate derivative.

[0358] (2) Add 67g boric acid, 162g tartaric acid, and 24g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 14:13:12. Then add 350mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0359] (3) Take 50g of the tartrate borate prepared in step (2) and completely dissolve it in 100mL of NMP. At the same time, add 119g of the product in step (1). The molar ratio of tartrate borate to the product in step (1) is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is a polycarbonate borate type polymer (X6-Y602) copolymerized from tartrate borate and polypropylene carbonate derivative.

[0360] Example 23

[0361] In this embodiment, a polycarbonate-based borate polymer (X7-Y603) was synthesized via a second copolymerization method, and its structural formula is as follows:

[0362]

[0363] n is a positive integer ≥ 1, and the curve represents a half bond.

[0364] Its preparation methods include:

[0365] (1) Add 1.6g of ethylene glycol and 153g of propylene carbonate to a round-bottom flask. The molar ratio of ethylene glycol to propylene carbonate is 1:60. Then add 0.25% sulfuric acid (based on the total mass of ethylene glycol and propylene carbonate) as a catalyst. React at 100℃ for 12h. After stopping the reaction, dissolve the product in N,N-dimethylformamide (DMF) and add LiOH aqueous solution to neutralize to pH=7. Remove the solvent by rotary evaporation. Continue to dissolve the solid product in DMF. Filter to remove insoluble matter, collect the filtrate, and dry to obtain a hydroxyl-terminated polypropylene carbonate derivative.

[0366] (2) Add 100g of the product from step (1), 4.3g of malic acid and 200mL of dry solvent NMP to a round-bottom flask equipped with a magnetic ball. The molar ratio of the product from step (1) to malic acid is 1:2. At the same time, add 1% of the catalyst 4-dimethylaminopyridine (DMAP) and 2% of N,N'-dicyclohexylcarbodiimide (DCC) (based on the total mass of polypropylene carbonate and malic acid). React at 80°C for 12h. After stopping the reaction, add a small amount of water, filter to remove insoluble matter, and remove water by vacuum distillation at 80°C to obtain an NMP solution of polypropylene carbonate derivatives with a carboxyl group and a hydroxyl group at each end.

[0367] (3) Add 68g boric acid, 174g diglycerol, and 24g lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 22:21:20. Then add 300mL of water as a solvent to completely dissolve the raw materials. Stir the reaction at 80℃ for 2h, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100℃ for 12h to obtain a white crystalline solid, which is tartaric acid borate.

[0368] (4) Take 50g of the tartrate borate prepared in step (3) and completely dissolve it in 200mL of NMP. At the same time, add 202g of the NMP solution (solid content 40%) of the polypropylene carbonate derivative synthesized in step (2). The molar ratio of tartrate borate to polypropylene carbonate derivative is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is the polycarbonate borate type polymer (X7-Y603) copolymerized from tartrate borate and polypropylene carbonate derivative.

[0369] Example 24

[0370] In this embodiment, a polyamide-based borate polymer (X1-Y701) was synthesized via the first copolymerization method, and its structural formula is as follows:

[0371] n is a positive integer ≥ 1, and the curve represents a half bond.

[0372] Its preparation methods include:

[0373] (1) Add 64g hexamethylenediamine and 83g terephthalic acid to a round-bottom flask. The molar ratio of hexamethylenediamine to terephthalic acid is 1.1:1. React under vacuum at 250℃ for 12h to obtain a poly(hexamethylene terephthalamide) derivative with terminal amino groups.

[0374] (2) Add 120g of the product from step (1), 6.5g of glycidyl ether and 200mL of solvent NMP to a round-bottom flask containing a magnetic ball. The molar ratio of the product from step (1) to glycidyl ether is 1:2. React at 80℃ for 10h. Remove the solvent by vacuum distillation to obtain poly(hexamethylene terephthalamide) derivatives with two hydroxyl groups at each end.

[0375] (3) Add 2.6g of boric acid and 12.5g of lithium hydroxide aqueous solution (solid content 8%) to a round-bottom flask containing a magnetic ball, and then add 300g of NMP solution of the product in step (2) (solid content 40%). The molar ratio of boric acid, lithium hydroxide and the product in step (2) is 1:1:1. Stir and mix thoroughly, remove solvent water and NMP by vacuum distillation, and dry under vacuum at 120°C for 24h to finally obtain a yellow solid, which is a polyamide borate polymer (X1-Y701).

[0376] Example 25

[0377] In this embodiment, a polyamide-based borate polymer (X6-Y702) was synthesized via a third copolymerization method, and its structural formula is as follows:

[0378]

[0379] n is a positive integer ≥ 1, and the curve represents a half bond.

[0380] Its preparation methods include:

[0381] (1) Add 115g of adipic acid and 150g of 4,4'-diaminodiphenyl ether to a round-bottom flask. The molar ratio of adipic acid to 4,4'-diaminodiphenyl ether is 1.05:1. React under vacuum at 250℃ for 12h to obtain a poly(diaminodiphenyl ether) diamine derivative with a carboxyl group at the end.

[0382] (2) Add 66g of boric acid, 155g of tartaric acid, and 24g of lithium hydroxide to a round-bottom flask. The molar ratio of boric acid, tartaric acid, and lithium hydroxide is 32:31:30. Add water as a solvent to completely dissolve the raw materials. Stir the reaction at 80°C for 2 hours, then remove the solvent water by rotary evaporation. Continue vacuum drying in an oven at 100°C for 12 hours to obtain a white crystalline solid, which is tartaric acid borate.

[0383] (3) Take 100g of the tartrate borate prepared in step (2) and completely dissolve it in NMP. At the same time, add 130g of the product in step (1). The molar ratio of tartrate borate to the product in step (1) is 1:1. React at 100℃ while removing water by vacuum distillation. Stop the reaction when no liquid is distilled out. Remove the solvent NMP by rotary evaporation. The product obtained is a polyamide borate type polymer (X6-Y702) copolymerized from tartrate borate and polypropylene carbonate derivative.

[0384] Performance testing of the borate polymers obtained in Examples 1-25

[0385] The basic properties of borate polymers were tested using the following method, and the results are shown in Table 1.

[0386] (1) Determination of molecular weight and molecular weight distribution of borate polymers: The absolute molecular weight (only the weight-average molecular weight is shown in Table 1) and molecular weight distribution of oligomers were determined by gel permeation chromatography-laser light scattering (GPC-MALLS). The gel chromatograph was a Waters 1515 GPC gel chromatograph and the light scattering detector was a DAWNHELEOS-II light scattering detector from Wyatt.

[0387] (2) Tests on the liquid absorption rate and conductivity of the gel polymer

[0388] A homogeneous polymer solution was obtained by dissolving a borate polymer in a good solvent, N-methylpyrrolidone (NMP). The polymer solution was then uniformly coated onto a substrate under low humidity conditions at -40°C. The substrate was then transferred to an 80°C forced-air oven to dry the solvent, and then transferred to a vacuum oven to dry at 100°C for 6 hours. After the solvent had completely evaporated, a dry film with a thickness of 30 μm was obtained.

[0389] The dried film was cut into circular film sheets with a size of 16mm*16mm, and the mass m0 of the film sheets was weighed. The film sheets were then immersed in 10g of dimethyl carbonate (DMC), a poor solvent, sealed, and stored at 60℃. After 1 hour, the film sheets were removed, and the DMC on the surface was wiped off to obtain a film-like gel polymer (i.e., a gel polymer film). The thickness and mass (m1) were measured, and its liquid absorption rate in DMC at 60℃ was calculated according to the following formula:

[0390]

[0391] The prepared gel polymer film was assembled with stainless steel gaskets, springs, etc. to form a 2032 type button cell. Impedance was tested at 25°C, and then the conductivity was calculated according to the following formula.

[0392] σ=L / RS

[0393] In the above formula, σ represents the conductivity of the gel polymer film (unit: S / m), which is the conductivity of the gel polymer; L represents the thickness of the gel polymer film (unit: m); R represents the impedance of the gel polymer film obtained by EIS testing using an electrochemical workstation; and S represents the area of ​​the gel polymer film (unit: m²). 2 ).

[0394] (3) Conductivity test of all-solid polymer

[0395] A homogeneous polymer solution was obtained by dissolving a borate-type polymer in the good solvent N-methylpyrrolidone (NMP). The polymer solution was then uniformly coated onto a substrate under low humidity conditions (-40°C). The solution was then transferred to an 80°C forced-air oven to dry the solvent, followed by drying in a vacuum oven at 100°C for 6 hours. After complete solvent evaporation, a dry film with a thickness of 30 μm was obtained and cut into circular film sheets measuring 16 mm * 16 mm, which are the all-solid polymer films (i.e., all-solid polymer membranes). The conductivity testing method is similar to that for gel polymers, except that the gel polymer film is replaced with the aforementioned all-solid polymer film.

[0396] (4) Test of the cation (lithium ion or sodium ion) mobility number of the gel polymer

[0397] The migration number of cations (lithium ions or sodium ions) was measured using the steady-state current method, as detailed below:

[0398] For the lithium-ion transport number test, the gel polymer film prepared in test (2) above was assembled with a lithium sheet to form a symmetrical battery with the structure Li / polymer film / Li. A small and constant potential difference ΔV (about 10mV) was applied to the symmetrical battery, and the change of current over time was observed. The initial current I0 and the steady-state current I were recorded respectively. s And the interfacial impedance R0 of the cell before polarization and the cross-sectional impedance R of the cell after polarization. s Then, calculate the lithium-ion transport number t using the following formula. + .

[0399]

[0400] For testing sodium ion transport number, simply assemble the polymer film and sodium sheet together into a symmetrical battery with the structure Na / polymer film / Na. The remaining test methods and calculation formulas are the same as those for lithium ion transport number testing.

[0401] (5) Cation (lithium ion or sodium ion) mobility number test of all-solid polymers

[0402] The method for testing cation transport number is similar to that for gel polymers, except that the gel polymer membrane is replaced with the all-solid polymer membrane prepared in test (3).

[0403] Table 1. Performance parameters of the borate polymers obtained in Examples 1-25

[0404]

[0405]

[0406] As shown in Table 1, the borate-type polymer of this invention, when it is an all-solid polymer, has an electrical conductivity ≥ 5.1 × 10⁻⁶. -6 When the S / cm is a gel polymer, the conductivity is ≥1.2*10. -5 S / cm. In Examples 1-4, since each repeating unit of the borate polymers X1-Y101, X1-Y102, X2-Y103, and X1-Y104 has only one Li + Ions, with low ionic conductivity; the gel polymer has a conductivity not exceeding 1.8*10. -5 S / cm, for all-solid polymers, not exceeding 6.5*10 -6 S / cm. In Example 5, the borate polymer X6-Y105, and in Example 6, the borate polymer X9-Y106, each repeating unit has multiple Li... + With increased lithium ion concentration, the ionic conductivity is significantly improved, and the gel polymer has a conductivity of not less than 5*10⁻⁶. -5 S / cm, for all-solid polymers, not less than 2.3*10 -5 S / cm. Examples 7-25 are borate polymers based on polyether, polyester, polycarbonate, and polyamide, respectively. Due to the presence of ion-conducting polymers such as polyether and polyester, the ionic conductivity is high, especially for polyether borate polymers X6-Y206, X8-Y207, and X11-Y208, polyester borate polymers X6-Y402, X7-Y403, and X10-Y502, polycarbonate borate polymers X6-Y602 and X7-Y603, and polyamide borate polymer X6-Y702. Each repeating unit has multiple Li... + The ionic conductivity of these types of gel polymers all reaches 4*10⁻⁶. -4 S / cm or higher. All of the above borate polymers, whether gel polymers or all-solid polymers, have a lithium-ion transference number > 0.9, indicating that the polymers in Examples 1-25 are all single-ion conductor polymers.

[0407] The borate polymers obtained in Examples 1-25 were applied to batteries, resulting in Application Examples 1-8, as detailed below:

[0408] Application Example 1

[0409] 1. Battery manufacturing

[0410] 1.1 Preparation of the positive electrode plate

[0411] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, carbon black conductive agent (Super) Li), PVDF binder ( 5130) was mixed in a weight ratio of 96.5:1.5:2 and added to a double planetary mixer. The total weight of the positive electrode active material, carbon black conductive agent, and PVDF binder was 1 kg. 0.5 kg of N-methylpyrrolidone (NMP) was added, and the mixture was thoroughly stirred. Then, 20 g of borate polymer X1-Y101 was added as an additive, and the mixture was stirred until homogeneous. The mixture was then filtered through a filter screen to obtain the positive electrode slurry, which had a solid content of 65%. The positive electrode slurry was then coated onto both sides of a 12 μm thick aluminum foil using an extrusion coating machine. After baking and hot rolling, a fully solid positive electrode plate was obtained. The areal density of the single-sided coating on the positive electrode plate was 4 mg / cm³. 2 The single-sided coating thickness is 12μm. The obtained positive electrode plate is dried in a vacuum oven at 120℃ for more than 24 hours to obtain the positive electrode plate.

[0412] The positive electrode plate was immersed in 2 kg of a mixed solvent of ethylene carbonate / ethyl methyl carbonate (EC / EMC, mass ratio 2 / 5), sealed and stored at 60°C. After 1 hour, the electrode plate was removed and the solvent on the surface was wiped off to obtain a positive electrode plate containing gel-state borate polymer.

[0413] 1.2 Preparation of negative electrode plate

[0414] The negative electrode active material is artificial graphite, and the conductive agent is carbon black (Super). Li), PVDF binder ( 5130) was mixed at a weight ratio of 97:1.5:1.5 and then fed into a double planetary mixer. The total weight of the negative electrode active material, carbon black conductive agent, and PVDF binder was 1 kg. 0.5 kg of N-methylpyrrolidone (NMP) was added and stirred thoroughly. Then, 40 g of borate polymer X1-Y102 was added as an additive, and the mixture was stirred until homogeneous. The mixture was then filtered through a filter screen to obtain the negative electrode slurry, which had a solid content of 55%. The negative electrode slurry was then coated onto both sides of a 6 μm thick copper foil using an extrusion coating machine. After baking and hot rolling, the negative electrode plate was obtained. The areal density of the coating on one side of the negative electrode plate was 2.7 mg / cm³. 2 The single-sided coating thickness is 16.5μm, and the resulting negative electrode plate is dried in a vacuum oven at 120℃ for more than 24 hours.

[0415] The negative electrode plate was immersed in 2 kg of a mixed solvent of ethylene carbonate / ethyl methyl carbonate (EC / EMC, mass ratio 2 / 5), sealed and stored at 60 °C. After 1 hour, the electrode plate was removed and the solvent on the surface was wiped off to obtain a negative electrode plate containing gel-state borate polymer.

[0416] 1.3 Preparation of electrolyte membrane

[0417] The borate polymer X1-Y201 was dissolved in a good solvent NMP to obtain a uniform polymer solution. The polymer solution was then uniformly coated onto a substrate under low humidity conditions of -40℃. The solution was then transferred to an 80℃ forced-air oven to dry the solvent, and then transferred to a vacuum oven to dry at 100℃ for 6 hours. After the solvent had completely evaporated, a dry film with a thickness of 30μm was obtained.

[0418] The dried film was cut into rectangular film sheets with a size of 56mm×50mm. The film sheets were immersed in 20g of ethylene carbonate / ethyl methyl carbonate mixed solvent (EC / EMC, mass ratio of 2 / 5), sealed and stored at 60℃. After 1 hour, the film sheets were removed and the solvent on the surface was wiped off to obtain a gel polymer electrolyte membrane.

[0419] 1.4 Cell fabrication

[0420] The positive electrode plate, negative electrode plate, and electrolyte membrane are cut into specific shapes. The active material area on the positive electrode plate is 48mm × 44mm, the active material area on the negative electrode plate is 52mm × 46mm, and the membrane is 56mm × 50mm. Current collector leads are left on both the positive and negative electrode plates. Then, the plates are stacked layer by layer in the order of negative electrode plate, membrane, positive electrode plate, membrane, negative electrode plate, ..., resulting in a total of 32 positive electrode plates and 33 negative electrode plates, with the outermost layer being the negative electrode plate. The current collector leads of the positive electrode plates are then welded together using an ultrasonic welder, and positive tabs are welded on. Similarly, the current collector leads of the negative electrode plates are welded together using an ultrasonic welder, and negative tabs are welded on. This yields the stacked body.

[0421] The aforementioned stacked bodies are placed into a packaging bag made of two stamped aluminum-plastic films, and the hot melt adhesive on the tabs is fused to the packaging bag by hot melting. The tabs are led out of the packaging bag, and an air bladder is left on one side of the packaging bag, thus obtaining the battery cell.

[0422] 1.6 Battery Formation

[0423] The battery cells are formed using a charging and discharging device. First, they are charged at a constant current of 0.05C to 3.6V. Then, a vacuum heat sealer is used to evacuate the air and seal the opening, and the air bladder is cut off. Next, they are charged at a constant current of 0.1C to 4.2V. Then, they are charged at a constant voltage until the current drops to 0.05C. Finally, they are discharged at a constant current of 0.1C to 3.0V, thus obtaining a formed battery.

[0424] Application Example 2

[0425] The difference between this application example and Application Example 1 is that the additive in the positive electrode plate is 10g X1-Y401, the additive in the negative electrode plate is 20g X2-Y202, and the electrolyte membrane is a gel polymer electrolyte membrane made of borate polymer X6-Y206. All other settings are the same as in Application Example 1.

[0426] Application Example 3

[0427] The difference between this application example and Application Example 1 is that the additive in the positive electrode plate is 10g X4-Y501, the additive in the negative electrode plate is 20g X1-Y301, and the electrolyte membrane is a gel polymer electrolyte membrane made of borate polymer X3-Y203. All other settings are the same as in Application Example 1.

[0428] Application Example 4

[0429] The difference between this application example and application example 1 is that the additive in the positive electrode plate is 20gX6-Y402, the additive in the negative electrode plate is 30gX2-Y204, and the electrolyte membrane is a gel polymer electrolyte membrane made of borate polymer X7-Y403.

[0430] The method for manufacturing the electrolyte diaphragm differs from that in Application Example 1. The specific method is as follows:

[0431] The borate polymer X7-Y403 was dissolved in a good solvent NMP to obtain a uniform polymer solution. The polymer solution was then uniformly coated onto a substrate under low humidity conditions of -40℃. The solution was then transferred to an 80℃ forced-air oven to dry the solvent, and then transferred to a vacuum oven to dry at 100℃ for 6 hours. After the solvent had completely evaporated, a dry film with a thickness of 30μm was obtained.

[0432] The dried film was cut into a rectangular film sheet with a size of 56mm×50mm. Then, a mixed solvent of ethylene carbonate / ethyl methyl carbonate (EC / EMC, mass ratio of 2 / 5) was uniformly sprayed onto the surface of the polymer film. The mass ratio of polymer film to EC / EMC was 1:0.4. After being fully impregnated, the polymer film was slowly removed from the stainless steel foil to obtain a gel polymer electrolyte membrane.

[0433] All other settings are the same as in Application Example 1.

[0434] Application Example 5

[0435] The difference between this application example and application example 4 is that the additive in the positive electrode plate is 20g X1-Y701, the additive in the negative electrode plate is 40g X8-Y207, and the electrolyte membrane is a gel polymer electrolyte membrane made of borate polymer X10-Y502. All other settings are the same as in application example 4.

[0436] Application Example 6

[0437] The difference between this application example and Application Example 1 is that the additive in the positive electrode plate is 25g X1-Y601, and the additive in the negative electrode plate is 35g X3-Y203. Furthermore, neither the positive nor negative electrode plate is subjected to organic solvent immersion treatment. The electrolyte membrane is an all-solid-state polymer electrolyte membrane made of borate-type polymer X11-Y208.

[0438] The electrolyte separator is prepared as follows: Borate polymer X11-Y208 is dissolved in a good solvent NMP to obtain a uniform polymer solution. Then, the polymer solution is uniformly coated on a substrate under low humidity conditions of -40℃. The solution is then transferred to an 80℃ forced-air oven to dry the solvent, and then transferred to a vacuum oven to dry at 100℃ for 6 hours. After the solvent has completely evaporated, a dry film with a thickness of 30μm is obtained. The film is then cut into rectangular sheets with a size of 56mm×50mm, which is the all-solid polymer electrolyte separator.

[0439] All other settings are the same as in Application Example 1.

[0440] Application Example 7

[0441] The difference between this application example and Application Example 6 is that the additive in the positive electrode plate is 10g X6-Y6O2, the additive in the negative electrode plate is 35g X5-Y2O5, and the electrolyte membrane is an all-solid polymer electrolyte membrane made of borate-type polymer X7-Y6O3. All other settings are the same as in Application Example 6.

[0442] Application Example 8

[0443] The difference between this application example and Application Example 1 is that the additive in the positive electrode plate is 10gX6-Y6O2, the additive in the negative electrode plate is 35gX5-Y2O5, and the separator is a commercially available PE separator with boehmite coating on both sides, with a thickness of 15μm. All other settings are the same as in Application Example 1.

[0444] Application Comparative Example 1

[0445] The difference between this comparative example and Application Example 1 is that the additive added to the positive electrode plate is a composite of 15g of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of the mass of PEO), and the additive added to the negative electrode plate is a composite of 30g of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of the mass of PEO). The electrolyte membrane is a gel polymer electrolyte membrane made of the composite of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of the mass of PEO). All other settings are the same as in Application Example 1.

[0446] Application Comparative Example 2

[0447] The difference between this comparative example and Application Example 6 is that the additive added to the positive electrode plate is a composite of 15g of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of PEO by mass), and the additive added to the negative electrode plate is a composite of 30g of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of PEO by mass). The electrolyte membrane is an all-solid-state polymer electrolyte membrane made of the composite of polyethylene oxide (PEO) and lithium bis(fluorosulfonyl)imide (LiFSI) (PEO molecular weight is 1,000,000, and LiFSI accounts for 8% of PEO by mass). All other settings are the same as in Application Example 6.

[0448] Application Comparative Example 3

[0449] The difference between this comparative example and Application Example 1 is that no additives are added to either the positive or negative electrode plates, and the separator is a commercially available PE separator with a boehmite coating on both sides, with a thickness of 15 μm. During the preparation of the dry cell, an air bladder and electrolyte injection port are left on one side of the packaging bag to inject the pre-prepared electrolyte.

[0450] The preparation methods for the electrolyte and the battery cell after electrolyte injection are as follows:

[0451] Lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio of EC to EMC 3:7) in a glove box with a dew point below -40°C to prepare an electrolyte with a LiPF6 concentration of 1.2 mol / L. Then, 1.5% by weight of vinylene carbonate (VC) and 1% by weight of 1,3-propanesulfonate lactone (1,3-PS) were added to obtain the desired electrolyte.

[0452] The electrolyte was injected into the dry cell through the injection port in a glove box with a dew point below -40°C. After standing for 24 hours, the injection port outside the air bladder was sealed with a vacuum heat sealer, and the gas in the cell was extracted to obtain the battery. The weight of the unformed cell was weighed, and the weight of the dry cell was subtracted to obtain the weight of the injected electrolyte.

[0453] All other settings are the same as in Application Example 1.

[0454] The batteries obtained from Application Examples 1-8 and Comparative Examples 1-3 were subjected to performance tests, including the following:

[0455] (1) Testing of initial discharge capacity

[0456] At room temperature, the formed battery is charged at a constant current of 0.1C to 4.2V, then charged at a constant voltage until the current drops to 0.05C, and then discharged at a constant current of 0.1C to 3.0V to obtain the first discharge capacity (Ah).

[0457] (2) Charge-discharge cycle test

[0458] At room temperature, the battery is charged at a constant current of 0.1C to 4.2V, then charged at a constant voltage until the current drops to 0.05C, and then discharged at a constant current of 0.1C to 3.0V. This cycle is repeated 100 times. The discharge capacity retention rate after 100 cycles at room temperature is calculated by comparing the discharge capacity of the last cycle with that of the first cycle.

[0459] (3) Acupuncture test

[0460] The battery needle penetration safety test was conducted in accordance with GB / T31485-2015. A steel needle with a diameter of 8 mm was used to penetrate the battery along the direction perpendicular to the electrode plate at a speed of 25 mm / s and remain inside for 1 hour.

[0461] The test results are shown in Table 2.

[0462] Table 2 Battery performance test results

[0463]

[0464]

[0465] As shown in Table 2, the batteries obtained in Application Examples 1-7 have lower internal resistance, higher energy efficiency, better rate performance, and better safety. This is because different borate polymers prepared in the examples were added as additives to both the positive and negative plates, and the electrolyte membranes were prepared using different borate polymers prepared in the examples. The gel-state (semi-solid) batteries obtained in Application Examples 1-5 have lower internal resistance, not exceeding 910 mΩ, and better cycle performance, not lower than 91%. This is because Application Examples 1-3 all used gel polymer electrolyte membranes prepared by immersion, while Application Examples 4 and 5 used gel polymer electrolyte membranes prepared by spraying. Furthermore, the positive and negative plates were also immersed in organic solvents to make the borate polymer additives gel-state. The all-solid-state batteries obtained in Application Examples 6-7 use all-solid-state polymer electrolyte membranes, and all-solid-state borate polymers are added to both the positive and negative plates. These batteries have relatively higher internal resistance and lower cycle performance.

[0466] In the all-solid-state battery obtained in Application Example 8, different borate polymers prepared in the examples were added as additives to both the positive and negative plates. The separator was a commercially available PE separator with boehmite coating on both sides. The internal resistance of the cell increased significantly, and the cycle performance was also average.

[0467] Both the semi-solid-state battery obtained in Comparative Example 1 and the all-solid-state battery obtained in Comparative Example 2 had commercially available ion-conducting polymer and small-molecule lithium salt composites added to the positive and negative electrodes, respectively, instead of the borate-type polymer prepared in this invention. The separator was also composed of a commercially available ion-conducting polymer and small-molecule lithium salt composite. Compared with the application example battery, the initial discharge capacity of the battery was significantly lower, and the cycle performance was poorer. Comparative Example 3 is a conventional liquid lithium battery with an electrolyte conductivity of approximately 8*10⁻⁶. -3 While exhibiting excellent electrochemical performance, including cycle performance, it caught fire during a nail penetration safety test, falling short of the high safety levels of Application Examples 1-8, which showed no fire or explosion. This highlights a problem with liquid batteries, particularly high-nickel ternary system liquid lithium-ion batteries.

[0468] The above are examples of the application of some borate polymers in batteries as described in Examples 1-25. Other borate polymers not listed can also be applied to batteries in the same way and achieve similar effects, which are beneficial to improving cycle performance and needle penetration safety.

[0469] In summary, this invention discloses a series of novel borate polymers and their preparation methods. These borate polymers are added to the positive and / or negative electrodes, and a gel or all-solid-state electrolyte membrane based on the novel borate polymers is used to prepare gel (semi-solid) or all-solid-state batteries. This invention solves the shortcomings of traditional gel polymer electrolytes and all-solid-state polymer electrolytes, such as low conductivity, low lithium-ion transference number, or low sodium-ion transference number. It improves the cycle performance and safety performance of solid-state batteries, reduces the risk of battery fire and explosion, and has great application prospects.

Claims

1. A borate polymer, characterized in that, The structure of the borate polymer is: (XY) n ,in, X is a cyclic group consisting of a hydrocarbon group or a substituted hydrocarbon group, B and O cyclized together, wherein the number of units in the ring is ≤20; Y is a short chain segment of a small molecule composed of a hydrocarbon group or a substituted hydrocarbon group, or a long chain segment of a polymer composed of a hydrocarbon group or a substituted hydrocarbon group. The substituted hydrocarbon group includes a halogenated hydrocarbon group, an oxygen-containing hydrocarbon group, a sulfur-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a nitrogen-containing hydrocarbon group; n is a positive integer ≥1; The structural formula of X is shown in general formula (2) or general formula (3) below: General formula (2); General formula (3); In this context, the curve represents a half bond; R1 and R2 are each independently selected from hydrocarbon groups, halohydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups, or amine-containing hydrocarbon groups; M is selected from Li and Na; W is selected from O and NR; R is a hydrogen atom or an alkyl group; and m is a positive integer ≥1. When the structural formula of X is as shown in general formula (2) or general formula (3), Y in the structure of the borate polymer is a short-chain segment of a small molecule or a long-chain segment of a high molecule containing at least one of hydrocarbon group, ether bond, amide group, imino group, ester group, and carbonyl group.

2. The borate polymer as described in claim 1, characterized in that, X includes at least one of the following structures (X6) to (X11): In this context, the curve represents a half bond; M is selected from Li or Na, W is selected from O or NR, R is a hydrogen atom or an alkyl group, and m is a positive integer ≥1.

3. The borate polymer as described in claim 1, characterized in that, Y includes at least one of the following structures (Y1) to (Y7): ； In this context, curves represent half bonds; R3 is independently selected from hydrocarbon groups, imino groups, oxygen-containing hydrocarbon groups, or nitrogen-containing hydrocarbon groups; R4 and R5 are independently selected from hydrocarbon groups or halogenated hydrocarbon groups; R6 is independently selected from hydrocarbon groups or substituted hydrocarbon groups; and x and y are both positive integers ≥1.

4. The borate polymer as described in claim 1, characterized in that, The number of elements in the ring is ≤12; And / or: the hydrocarbon group has 1-5 carbon atoms; And / or: the haloalkyl group has 1-5 carbon atoms; And / or: the sulfur-containing hydrocarbon group has 1-5 carbon atoms; And / or: the nitrogen-containing hydrocarbon group has 1-5 carbon atoms; And / or: the oxygen-containing hydrocarbon group has 1-10 oxygen atoms; And / or: The oxygen-containing hydrocarbon group is selected from hydrocarbon groups containing -C=O, -O-, -(C=O)- or -COO-.

5. The borate polymer as described in claim 4, characterized in that, The number of elements in the ring is ≤8; And / or: the hydrocarbon group has 2-4 carbon atoms; And / or: the haloalkyl group has 2-4 carbon atoms; And / or: the sulfur-containing hydrocarbon group has 2-4 carbon atoms; And / or: the nitrogen-containing hydrocarbon group has 2-4 carbon atoms; And / or: the oxygen-containing hydrocarbon group has 2-5 oxygen atoms; And / or: The oxygen-containing hydrocarbon group is selected from hydrocarbon groups containing -C=O, -O-, -(C=O)- or -COO-.

6. A method for preparing a borate-type polymer as described in any one of claims 1-5, characterized in that, The borate polymer is synthesized via copolymerization, and the copolymerization method includes two types, wherein... The second type of copolymerization involves a dehydration condensation reaction between the first substance containing Y and the borate containing X and the inorganic salt containing M, resulting in a borate-type polymer linked by borate groups, as shown in Formula II. Formula II; The third type of copolymerization involves a dehydration condensation reaction between the second Y-containing substance and the X-containing borate to generate a borate-type polymer linked by borates, as shown in Formula III. Formula III; R1 and R2 are each independently selected from hydrocarbon groups, halohydrocarbon groups, oxygen-containing hydrocarbon groups, sulfur-containing hydrocarbon groups or amino-containing hydrocarbon groups, M is selected from Li and Na, W is selected from O and NR, R is a hydrogen atom or alkyl group, m and n are both positive integers ≥1, and the curve represents a half bond. In the second copolymerization, the first Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows: In this context, N1 is independently selected from either a hydroxyl or a carboxyl group; In the third copolymerization, the second Y-containing substance is a small molecule or polymer containing Y, and its structural formula is as follows: In this context, N2 is independently selected from hydroxyl, carboxyl, or amino groups; In the second and third copolymerizations, the X-containing borate is a cyclic polymeric borate with borate groups at both ends, and the X-containing borate is synthesized from boric acid, an inorganic salt containing M, and an organic compound containing hydroxyl or carboxyl groups; In the synthesis of the second copolymerization, the third copolymerization, and the X-containing borate, the M-containing inorganic salt is either an inorganic lithium salt or an inorganic sodium salt.

7. The preparation method according to claim 6, characterized in that, The first Y-containing substance is a Y-containing small molecule or Y-containing polymer with two hydroxyl groups, two carboxyl groups, or one hydroxyl group and one carboxyl group at each end.

8. The preparation method according to claim 6, characterized in that, The second Y-containing substance is a Y-containing small molecule or Y-containing polymer with a single hydroxyl group, a single carboxyl group, or a single amine group at both ends.

9. The preparation method according to claim 6, characterized in that, The first Y-containing substance is obtained by chemical modification of the second Y-containing substance; And / or, the organic compound is at least one of tartaric acid, pentaerythritol, diglycerol, bis(trimethylolpropane) and ethylenediaminetetraacetic acid.

10. An electrolyte, characterized in that, The electrolyte comprises the borate polymer as described in any one of claims 1-5 or the borate polymer obtained by any one of the preparation methods described in claims 6-9; The electrolyte is a single-ion conductor polymer electrolyte.

11. The electrolyte as claimed in claim 10, characterized in that, The single-ion conductor polymer electrolyte is an all-solid polymer electrolyte or a gel polymer electrolyte, with a cation transference number > 0.9, and the cation is either lithium ion or sodium ion.

12. The electrolyte as claimed in claim 11, characterized in that, The ionic conductivity of the all-solid polymer electrolyte is ≥5*10⁻⁶. -6 S / cm.

13. The electrolyte as claimed in claim 11, characterized in that, The liquid absorption rate of the gel polymer electrolyte is 1%-1000%.

14. The electrolyte as claimed in claim 13, characterized in that, The liquid absorption rate of the gel polymer electrolyte is 1%-500%.

15. The electrolyte as claimed in claim 14, characterized in that, The liquid absorption rate of the gel polymer electrolyte is 1%-300%.

16. The electrolyte as claimed in claim 11, characterized in that, The ionic conductivity of the gel polymer electrolyte is ≥1*10 -5 S / cm.

17. The electrolyte as claimed in claim 16, characterized in that, The ionic conductivity of the gel polymer electrolyte is ≥1*10⁻⁶. -4 S / cm.

18. A diaphragm, characterized in that, The diaphragm comprises a borate polymer as described in any one of claims 1-5 or a borate polymer obtained by any one of the preparation methods described in claims 6-9; The diaphragm is a single-ion conductor polymer diaphragm.

19. The diaphragm as claimed in claim 18, characterized in that, The single-ion conductor polymer membrane is an all-solid polymer membrane or a gel polymer membrane, with a cation transference number > 0.9, and the cation is either lithium ion or sodium ion.

20. The diaphragm as claimed in claim 19, characterized in that, The ionic conductivity of the all-solid polymer membrane is ≥5*10 -6 S / cm.

21. The diaphragm as claimed in claim 19, characterized in that, The liquid absorption rate of the gel polymer membrane is 1%-1000%.

22. The diaphragm as claimed in claim 21, characterized in that, The liquid absorption rate of the gel polymer diaphragm is 1%-500%.

23. The diaphragm as claimed in claim 22, characterized in that, The liquid absorption rate of the gel polymer membrane is 1%-300%.

24. The diaphragm as claimed in claim 19, characterized in that, The ionic conductivity of the gel polymer membrane is ≥1*10 -5 S / cm.

25. The diaphragm as claimed in claim 24, characterized in that, The ionic conductivity of the gel polymer membrane is ≥1*10 -4 S / cm.

26. A battery, characterized in that, The battery is one of a lithium-ion battery, a sodium-ion battery, a lithium metal battery, or a sodium metal battery, and the battery includes a borate polymer as described in any one of claims 1-5 or a borate polymer obtained by any one of the preparation methods described in claims 6-9; Both the lithium-ion battery and the sodium-ion battery are single-ion conductor polymer batteries.

27. The battery as claimed in claim 26, characterized in that, The single-ion conductor polymer battery includes a positive electrode plate, a negative electrode plate, an separator, and an electrolyte; wherein the positive electrode plate contains the borate polymer; and / or the negative electrode plate contains the borate polymer; and / or the separator contains the borate polymer; and / or the electrolyte contains the borate polymer.

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